I've been using Google Flights since the middle of last year and love it. However, as a frequent traveler for business/conferences, I think there are some things people should be aware of:
* Google's data seems to be not as fresh as Kayak or Hipmunk's is. There have been multiple times when I've tried to book a flight via GF only to be told that there were no seats left when I arrive on the airline's page. I suspect part of the greatly improved speed comes at the cost of aggressive caching that runs a risk of things being out of date.
* Google's data is all over the map on pricing. Very frequently the airline's price will be much cheaper than GF. And more than once (especially on United or American Airlines) I've noticed that if I book directly through an airline over a VPN, I save several hundred bucks versus if I click through from Google Flights or Kayak. Conversely, sometimes GF is less expensive and when I land on the airline's page it's more expensive.
I think the best thing to use it for is route discoverability: which kind of planes and which airlines fly to which locations, on which days at which times? It's also great for doing complex open-jaw routes or hidden-city fares -- and since those routes don't change very often, the data is more likely to be accurate.
I've had nearly the identical experience with it on all counts. By and large, I am a huge and loyal user of it as well.
It seems I've had the most changes in fare price or availability when identifying flights on United specifically, more so than any other airline, in my experience. That being said, it's still pretty infrequent given the volume of airfare we've booked through it for our people over the last 2 years or so.
Another thing I would add is that in connecting flight situations, it will occasionally present an itinerary that's technically possible to make, but not always entirely practical or ideal. (e.g. the window between flights is really narrow, not leaving much margin of error for flight delays, getting to another gate/terminal, etc., if not near the one you arrive at.)
All that being said, it really does work pretty great and we prefer using it to any of the other travel sites.
I would love to know why there are occasional fare discrepancies though... as far as I know google treats the click-through to the carriers' sites like an ad click, so I don't think Google is "marking it up," rather, the carriers are in some cases pricing based on the referer link or something. It can also be a demand pricing issue too, as the flight fills up, I suppose. My understanding is that Google is basically just the informational conduit between the user and the airline so it's weird that there are occasional price discrepancies.
Short answer re price discrepancies: it's complicated. It's absolutely in our interest and the airlines' interest to get pricing 100% right, and we do work really hard to eval and improve on this.
One situation that can happen is that an airline has, say, 3 seats remaining at one fare and 1 seat remaining at a cheaper fare; when you selected the flights or immediately before, that 1 seat was still available, but by the time you click through, it's not, so you get the pricing for the fare with 3 seats left.
One of the things that's amazed me in my flights education after joining the team is just how super-dynamic pricing is.
No, to my knowledge it's not based on your referrer or cookies or anything like that ;). I'm just talking -- person-independent -- pricing from hour to hour.
On a related note, I used to think that airline pricing was pretty capricious and random; now I realize that the airlines hire some of the smartest folks to develop pricing strategies, and nothing is left to chance ;).
Assuming you're on google.com/flights, I'm fairly sure that using a VPN, changing your IP, flushing your cookies... none of that should change the availability and pricing you see on Flights.
And no, don't bother trying to time your bookings. It's kinda like the stock market; trying to beat the market, er, optimize your flights purchase time is likely to lead to sorrow and regret. From the research our Google Flights team did recently, we found that if you wait a week, on average you're gonna pay more for the same flight.
And no, we didn't see any universal discount on Tuesdays, either ;)
I only have one VPN, GoldenFrog's VyprVPN service. Sorry, I didn't intend to suggest that I was running multiple VPNs.
I haven't experimented extensively with things, but usually setting my exit server to a random country on the other side of the planet (e.g. Malaysia) has yielded consistently good results.
The big trend in the airline industry is to customize prices and availabilities to each individual request. Your ___location (IP address), your frequent flyer status (if logged in), the competitor's current prices, the distribution channel (e.g. web or travel agent, GDS) will all have an influence on what is presented to you. Meta search engines have had a difficult time reporting accurate fares even in the past when it was much simpler. In the future, it'll be almost impossible.
My own very small data point is booking a few flights for our Executive (2013, former company), and my own (recent 2015) flights, which had the correct flight time/date on Google Flights, but when "ordering" from the sight, were munged into different dates.
I love the flexibility this has and after giving it a serious go I never went back to Kayak.
If you know exactly when and where to fly, Kayak is great. But with any uncertainty, Google Flights is better for exploring. Maybe you know when to fly, but not when you want to come back. Or maybe you don't even know where you want to fly, in which case you can get destination suggestions. It's also a lot snappier.
Now with this flight data they have, I'd imagine being able to just use Google Maps route search to go from A to B such that it would also include flights where applicable. While it kind of does, I am still able to think better routes myself. For example if I search from Tokushima, Japan -> San Francisco, USA, it suggests I should fly from Tokushima. Where actually it's a lot cheaper with almost no time difference to go by bus to Osaka first instead.
The best thing about Google Flights is how fast it is. The +/- 3 days (or whatever) options are never really exactly what you want, and while Google Flights also doesn't let you execute really powerful searches, you can at least manually search at a rapid pace (<1 second per search rather than >10 seconds on other sites).
IshKebab, we really do work hard to make Flights fast (the amount of data we have to keep cached is pretty insane, IMHO!); thanks for the kind words!
re searches... it's our hope that -- for most folks and most cases -- our filters + our tips will suffice. But if there are specific power features you're looking for, let us know via the Feedback option and I'll do what I can to bribe, er, win over my teammates :p
Did you actually try to book the flight by following the links on both Google and Kayak? Google is showing the flight at $1809 now and it's possible that their cache was not updated.
Also, it's possible that flight is under KLM/AF instead of Delta on Kayak since Delta/KLM/AF are partners. And I see same flight listed under KLM for $1781.
It would be interesting for a travel engine to list the alternate routes and options and let people vote ion each option to provide weighting to each one based on peoples preference for each.
I wasn't even aware of Google Flights until I saw the article posted on HN. Go figure...
For some of us, the constant deluge of info, along with work and family life, makes it tough to stay on top of all the latest developments. Glad this service was "re-announced".
There's lots of travel sites popping up all the time, including accommodations sites. That's why I built http://AllTheRooms.com, which aggregates all the different accommodations sites and deals sites, like Expedia, Groupon, Hotwire, and Airbnb
I'd update your copyright footer, if only because at a glance it makes me wonder if it's unmaintained.
I've been wanting a more powerful hotel search site for many years, but I think most of the features I'd care to see are limited by the messy data available about the properties (amenities, etc.) and the margins just aren't there to support an aggregator curating their own data. Maybe not even for a reseller like Hotels.com.
yekim, we (working on Google Flights) hear this again and again. AAAAAAAGH! :o
I hope you're enjoying the service, and we'll see what we can do about getting out the word a bit better ;).
P.S. -- You'll be amused to know that -- seriously, just today -- I was telling a colleague about this cool thread on HN, and he said, "Wait... hackers? Wha... huh?" I guess he also has work and a family life :p
Their hotels searching is still pretty rough. It's not very googly, in that it's mostly pay to play. You have to look hard to find nonpaid content. It also leaves out all the lower cost options like Airbnb. I built http://AllTheRooms.com to aggregate everything, including sites that don't pay, because Google wasn't really doing its job in the accommodations space.
You don't always pay additional fees through a third party. If only flight ticket pricing was that easy. There have been instances when I found better deals on other sites compared Google (all of them happen to be international flights).
True, there are not always fees, but they are around. International flights have been a bit harder on all of the major US based flight searches though, right? Have not flown international in quite some time, so not as familiar with them.
Awesome. I can never understand what antiquated database and UI the other flight reservation websites are using. Simple database queries take 10+ seconds, and then you have to click N more times to get the taxes included.
Why can't I query for
SELECT * FROM tickets WHERE sqrt((destination_latitude-desired_latitude)^2 - (destination_longitude-desired_longitude)^2) < 5000 AND abs(unix_timestamp(departure)-unix_timestamp('somedate'))<10*86400 ORDER BY (price+taxes+fees);
with proper geoindexing and sharding this query should take no more than a fraction of a second, yet airline websites want me to use some stupidly-designed UI that can't implement above query, takes 10+ seconds to return results, and doesn't include the taxes and fees. Thus I need to often manually enter every destination within 5000km and every date combination and manually waste half a day to find the cheapest ticket to "anywhere interesting".
Furthermore often times changing the language and country of the website changes ticket prices; a well-designed, globally-consistent database should not allow this to happen.
I hope that Google will disrupt and reengineer this ancient system.
Most companies don't want to take on this complexity, so they outsource it. The companies that provide this service, like ITA, tend to charge more money for more expensive queries, like multi-day searches, so most online search companies will only let you do the cheaper kinds of searches.
I wonder if it would be viable to start an airline whose business model is "simple pricing". Just forget ITA altogether, sell tickets directly, and have the pricing model extremely simple. Like, total price = C/(time to departure) for some constant C, and use machine learning, or just a simple PID feedback loop on revenue to set C in order to be profitable.
As the presentation above suggests, this would have a problem with, well, staying profitable. Tourist air travel is so heavily underpriced that you can barely tank up the jet with what you collected from people. That's one of (or maybe even the) reason for such variety in ticket prices.
Airlines spend a absolute fortune on complex pricing for a reason... they wouldn't survive (in the absence of protectionism or a natural monopoly on niche routes) without it. The optimum "one size fits all" price doesn't exist.
I don't think this would work unfortunately. Players in air travel face a) intense competition and b) tiny profit margins. This forces some 'creative' pricing.
For the same reason I can't just renew a ___domain at Network Solutions without going through eight different pages trying to upsell me things (and often defaulting to checking on those services).
Expedia, Orbitz, etc make money via nag screens and upsells. They have no incentive to make the experience positive or easy. Google seems to.
I've switched from 1&1 to gandi.net - and while they are a little more expensive it's been pretty smooth. Also they support TOTP which is a huge awesome in my book (I used TOTP with facebook, Microsoft account, google, source code committing etc).
I'm convinced that for every DNS related change at 1&1 - there is a guy that manually makes the change.
I switched to Namecheap; they sell stuff but are not annoying about it.
Google Domains also looks promising but I'm waiting for them to not be in beta lest they decide to scrap the product. Google would win me over if they offered free SSL certificates. In fact I think they should go ahead and disrupt the SSL industry by doing that too. Nobody should have to pay for a silly cryptographic signature. That would disrupt NS and all the others who try to upsell stuff.
> […] if they offered free SSL certificates. In fact I think they should go ahead and disrupt the SSL industry by doing that too. Nobody should have to pay for a silly cryptographic signature.
> ...free SSL certificates. In fact I think they should go ahead and disrupt the SSL industry
StartSSL already offers free SSL certificates - and they haven't disrupted the industry. Even if Google started offering free SSL certificates - it's only a band-aid to the problem not a solution.
Have you tried using StartSSL??
(a) They aren't free if you are doing anything 'commercial'
(b) I decided to try and give them my money. I tried very hard. I gave up.
After uploading your documents 30 times, them claiming they didn't get them, you would too.
Oh, and uploading them each time was pretty painful.
Yeah, this is terrible engineering design IMHO. The providers should just provide some kind of firehose of updates to the booking websites which can then cache the data appropriately.
Also they should fix their cache implementations. I've had countless times on the AA website where it says a ticket is available; then when I try to book it it says it's not available; then when I go back to the home page and search again the same fare shows up again. Seriously, where do their programmers come from ...
There are basically an unlimited number of world wide routes - a mind blowingly dizzying number of permutations to get from A to B.
Before you try to say "well travellers won't want routes with feature X" to cut down on the volume of data travellers want all sorts of contradictory things. Some a vastly price sensitive, some hate a particular airline, some love that same airline, some are time sensitive, some change those preferences depending on whether they are flying domestic or international, with or without kids.
> a mind blowingly dizzying number of permutations to get from A to B.
Yes, but I don't think that's what most people desire to enumerate (or what the parent of your post had in mind). A simple enumeration of the flights available and their one-way prices would be a start. My understanding (from a link in another post) is that this would be ~(1 flight) * (average number of changes to a flight's data between birth and flight) updates per second, which I think is within reason.
My understanding is that airlines frustrate this by not pricing just individual flights, but giving odd discounts on round-trips and other odd combinations (such as A→B C→A) of flights, meaning you need more than just one-way prices. (There's also the fact that some airlines have like 5 or 6 different prices for a seat all on the same flight, depending on where in the plane the seat is.)
There's all kinds of reasons that this isn't sufficient, return based pricing, multiple seat pricing bands for a single flight (for some airlines this is dynamically calculated on a moment-by-moment basis), airline and airports rules covering transfers for whether a given pair of flights connect or not, etc... the list is basically unlimited.
Yeah, well, if you can get providers to agree to do anything at all, let alone have the capability to not be in the engineering dark ages, you'll be rich. Until then, companies will continue to fill the gap with imperfect solutions.
So we need an API to search all the languages and countries, pay in the appropriate currency, abstract this "feature" away along with the language barrier, and give me the lowest price. I hope Google will do that. :)
It would likely break all sorts of TOS agreements at various levels, and wouldn't last a month.
There are industries where profits are huge and disruption is badly needed. Airlines are not one of them, afaik; ever since low-cost became a thing, they've been under constant economic pressure and usually operate on razor-thin margins, at least in Europe. Mid-size companies have all but disappeared, even giants like British Airways and KLM have been permanently de-structured.
Flying is an expensive and risky business, piling up the pressure is likely to generate even more safety issues than we already have today. If you're all about price, just fly with RyanAir and be sure that nobody can ask you for less money than they do.
Oh the big consolidated IATA airlines are raking it in, don't worry about them
"On a per passenger basis, [IATA] airlines will make a net profit of $7.08 in 2015. That is up on the $6.02 earned in 2014 and more than double the $3.38 earnings per passenger achieved in 2013."
Decentralization to the rescue? Create a decentralized system by which such scripts can be circulated and updated without anyone owning them.
In general I live by (0) anything that can be scripted and automated should be automated and (1) humans and machines are no different and the boundary between human and machine will blur in the future, so we might as well stop differentiating the two now, assume the customer is infinitely smart, and define all policies and business models using only initial state and final state of the customer rather than the process the customer went through to reach that state.
For example, my library books can be renewed online (or else one pays a fine). This can be automated. Thus, I write a script to abstract this problem out of my life. The library need only care when the loan out and when they get back, everything else about the system including whether it's a collection of silicon components or a collection of sodium-potassium-pump components that causes the state transitions at book renewals is none of their business. If I invented something that used germanium to cause a renewal (and biologists can't figure out whether to define it as living or nonliving, intelligent or nonintelligent), the library shouldn't care.
Similarly, it's none of the airline's business whether it's sodium-potassium, silicon, or germanium that transfers entropy about tickets; the initial and final states are the same. if I can gain information about airline tickets by manually querying 1000 times from different parameters, that process should be scripted and automated.
I'm a machine just like my computer, just a much slower one.
Hey everyone, just spotted this thread and was really happy to see all the comments about Google Flights. Though I've been at Google for nearly 9 years, I'm pretty new to the Flights team, so there's still a lot I'm learning... but I'll try to tackle at least few questions below :)
(I'm also both an oldtimer and newtimer to HN; long time lurker, and I opened an account ages ago, but sorry I've not been active here before!)
This site allows users to search for hidden city ticketing. There are some good instruction pages out there. I've never personally used it since I live in Canada and spoke and hub isn't really a thing up here.
Right, that is a definite feature of some fares. They allow a free stopover at their hub if you want. Given that, almost all fares allow a 23 hour connection without it having to be programmed into the fare.
And I didn't mean it was a scam, more like a cool hack.
That's where the money comes from -- and ITA's mission was to be a backend for other people, who would deal with the expensive customer service side themselves.
Presumably as a Google service, customer service isn't a priority anymore.
That's very interesting to me. Either they're getting data from the same place and marking the price up differently or they're getting data from separate places that are marking the prices up differently.
I think that everyone should be getting their data from the same place, one of the major reservation systems, depending on the airline. For example, if you are looking at British Airways, it is served by Amadeus.
Hey radiorental, if you're seeing a persistent issue with a particular city pair, please let us know via Google Feedback. On Flights, click Help, then Send Feedback. We read this stuff and while a lot of issues aren't simple quick fixes, we're hardcore about comprehensiveness and accuracy re availability and prices!
I've used Google Flights before, but I almost always end up flying Southwest, which doesn't disclose their prices to aggregators. Does anyone know if Google has tried to strike a deal with them? If anyone could, I imagine it would be Google.
I suppose someone could get bold and attempt to do some scraping. Of course, my money would be on SouthWest stopping this behavior as a violation of their terms of service.
They explicitly take ownership of the content, mention that the information is only for non-commercial use, exclude use of the information on their site for commercial use and additionally use for any other purpose. In case their message is not clear, they go even further and list a variety of prohibited activities.
The language of their Terms & Conditions is rather broad. It looks like virtually any activity on their website as a violation. Perhaps that is now the norm.
Incidentally I reserved two tickets yesterday after finding the best prices with Google Flights. It linked me directly to the airline's reservation system a couple of clicks away from confirmation.
BTW, I used their map to find the most suitable flight. I could change dates on the fly and see the prices change instantly. It's a great service.
Now if they could do the same for railways, I'd gladly pay for the convenience.
I want to be able to search by criteria like "somewhere sunny", "the mediterranean", "somewhere to party in the summer", etc. I thought this was it, but not quite :-(...
I've been using Momondo recently, which has all of these tools and a much better UX. This just feels like a re skin of the ITA site and a bit of a poor effort at that.
How is it that we were able to land a man on the moon over 45 years ago and we still can't just type in a search engine and get the cheapest flights from point A to point B on certain dates?
I find this really baffling. It is a service all customers want yet even the great Google can't seem to provide this.
Meanwhile Google puts out so many "experimental products" that they later dispose.
There is talk of Google getting into cell-phone service and the are already getting into Google fiber. I wish Google would use its pricing power and buy entire flights between major cities domestic and international (eg, NYC to Chicago, LA, SF, Miami, Atlanta, and London).
Moreover, an airline can really make its profits on airline fuel speculation since this is the most volatile component of airline costs.
> How is it that we were able to land a man on the moon over 45 years ago and we still can't just type in a search engine and get the cheapest flights from point A to point B on certain dates?
Because the airlines have their own army of geniuses working very hard to make sure that this is difficult to do:
Who are you? How much money do you have? How badly do you want these tickets? How often are you checking the price, what else have you bought? How are your buying habits compared to everyone else's? These are the questions the airlines are trying to answer in order to maximise how much money they can get off each individual.
Wow. So as a United "elite" member, just doing searches on their app or site but with my account, is gonna cost me? Because I've never seen this happen. I seem to get the lowest fare they have. I've not done serious tests, just seen when other people look up my flights, on say, Kayak, they get the same prices.
Try browsing for tickets with and without private browsing enabled, and from different geographic IP addresses, from different computers, and different websites (cheapair, Expedia, Orbitz...). You should definitely see a fluctuation in prices, for the same seats. I always do.
It may well be that elite members get lower prices, as this may be the way for the airline to maximise their profit off you. Their algorithms are quite inscrutable, intentionally so.
Landing a man on the moon was not an adversarial problem, whereas flight bookings are. If flight bookings were like you want them to be, airlines might find themselves asking how we were able to land a man on the moon over 45 years ago, but can't create a booking system that makes it sufficiently difficult for consumers to find our cheapest flights?
Unsurprisingly, we're somewhere between the two. Most determined people can find flights that are at least close to being the cheapest.
I would love GF to have a feature where you select a departure airport and arrival airport and dates, and make GF find me where to go in between. Like a search with multiple cities but so that you decide the departure city of the first flight and the arrival city of the second flight.
1) When I go to the front page (https://www.google.com/flights/), everything from and including the 'return/one way/multi stop' row down is fixed-width at about 650px even when my window is far larger. This sort of fixes itself once I start selecting cities, but is randomly narrower than the auto-sizing search bar + other stuff above it. I'm on Win7 x64 / FF 36.0.
2) Please localise currencies. You auto-detect me in Brisbane, Australia. If I pick a flight to Sydney on AU carriers, I don't care about prices in USD. You either convert it to USD in the first place (or just assume 1AUD=1USD) but don't when you display it to me.
I used Google Flights back in November to plan a 10-day getaway during December. BWI->MIA, MIA->LAX, SFO->BWI. Total airfare cost: $420. It was far easier to do this with GF than with Hipmunk or any other website i'd tried.
Minor: got a certificate error when I clicked on this url. However that disappeared when I manually typed in www.skypicker.com in the browser. Most likely cause it seems is because their site certificate is *.skypicker.com
I've been using this for quite some time... works very well. I only will fly one or two airlines, but I still use Google Flights to compare days, and departure airports because its so much easier!
There are sites dedicated to scouring and curating the best deals found using the ITA Software Matrix. http://Theflightdeal.com is the best that comes to mind. http://PointsBuzz.com also aggregates the various different sites focused on flight deals and maximizing frequent flyer points for the most worthwhile trips.
Open-ended destination is great, but I've sometimes wished for open-ended source. My usecase is something like a casual multi-stop trip, where you have an eventual destination in mind, but would like to save money, or see where else you can go along the way for a similar amount of money.
I've worked around it by manually checking nearby routes, or getting a feel for options with open-ended reverse flights and then searching the reverse again.
I'm a fan of https://www.vamo.com/ for multi-city trips. You put in your point of origin and all the cities you want to visit (and for how long), and it routes you between the cities on the best type of transportation and offers accommodation suggestions as well.
I used to be a hardcore Hipmunk user and I still think I prefer it to Google Flights. I had some trouble recently with Hipmunk linking to flights that don't exist on the airline's websites. I've been using Google Flights ever since. Hopefully Hipmunk will get things back in order again.
Hmmmm. I'm searching New York to Europe (March 25th to April 23rd) and it's giving me a $303 round trip to Madrid. Thats absolutely incredible, but when I click through the fair jumps to over $800. Anyone else experiencing things of that ilk?
Minor complaint: the first thing I tried to do was try to find a flight from anywhere in the UK to anywhere in Slovenia. Whilst it lets me be vague about my destination, it doesn't seem to about my starting point... Skyscanner lets me do this
BS. Non-business flights are the most price-sensitive type of product there could possibly be.
Near 100% of people only apply a few very basic filters, e.g. no 12-hour layovers, doesn't depart at 5am, and then choose the cheapest. It's not some sophisticated "balance" that needs some advanced machine learning or personalization to accomplish. It's a few obvious filters that are the same for practically everyone.
I'd love to see partial dependance plots for each of the obvious filtering factors, vs how often people chose that flight. That's the best way to do this type of analysis.
Not to mention that many times the cheapest flight listed on these travel sites isn't actually available when you try to book it. Wonder how that may have skewed Google's analysis.
Hey solve, I thought the exact same thing you did! But then -- as someone who recently joined the Google Flights team -- I helped lead some research that included this topic... and was honestly surprised to find that about 40% of the folks searching on Google Flights DON'T pick the cheapest flight.
Price, certainly, is still a huge factor in folks' decision, but convenience plays a very significant role. And, from anecdotal evidence (not part of the same research), brand loyalty is definitely a factor as well (a very price sensitive travel blogger I know still prefers to fly on American, for instance).
Search engines are all about aggregation, it seems like a logical step for them.
Bing, Yahoo, and even AOL also have their own travel sites, so it is not just the dominant search engine, it is all of them.
It is also nice to not have to support some third party by buying tickets through them. Just compare the prices and go directly to the airline.
> The difference is, if I type WAW to LHR into Google, I get flight listings with prices and availability.
Yes, and I think that's a Good Thing. Google rightly knows that when I type "WAW to LHR", I want to know about the flight, not about where to find out about that flight.
An implication of this difference is that google probably charges for that convenience by saving your itinerary somewhere and selling it to your insurance company.
But how is that different from typing "2+3" or "what is the speed of light?" or "what is the temperature in San francisco CA?" in the Google search bar? I think it is all about convenience.
Any personal assistant app can't do away from this aggregations. These are the first and low hanging fruits when it comes to personal assistants, given that more and more the personal assistants and the search engines will morph into one.
I stumbled across Google Flights a couple of years ago back when it wasn't as pretty, but I've always found it to be incredibly useful, at least for traveling in the continental U.S.
I just used this to book my flight to PyCon 2015 oddly enough. It was pretty damn easy to use and let me jump from its search results to directly booking with Air Canada. Pretty smooth...
I just ran a comparison with Expedia (which seems to no longer be ASP.NET based as an aside); not too surprised, Expedia found the cheaper flights. Read, cheaper, not necessarily better.
The UI/UX on this product is not that great. Google is offering a similar solution as Kayak. But I'm not sure why they just didn't fully copy Kayak. It feels to me, 1 - google thinks they are smarter than Kayak, 2 - they didn't want to show they are copying Kayak.
For example, kayak does a great job of displaying all the options on the left column. Google is hiding everything in drop downs. So then they need to have a blog post to explain how their UI works where kayaks is just intuitive.
The same with bar chart pricing (which I like) why hide it behind a silly icon like that. Now they have to educate their users what that icon means. Call it "best days to fly" or even better show that at the bottom of the page.
I disagree. I spent nearly a year as a UI designer/engineer for a flight search/booking tool and evaluated all the major interfaces. The #1 killer feature google flights has which kills all other flight search tools (I have seen) is speed. They bought a company (ITA) for something close to a billion dollars which provides near realtime search results for flights.
Kayak (and others) do a good job of streaming search results, but you still have to wait seconds before you're able to make decisions.
* Google's data seems to be not as fresh as Kayak or Hipmunk's is. There have been multiple times when I've tried to book a flight via GF only to be told that there were no seats left when I arrive on the airline's page. I suspect part of the greatly improved speed comes at the cost of aggressive caching that runs a risk of things being out of date.
* Google's data is all over the map on pricing. Very frequently the airline's price will be much cheaper than GF. And more than once (especially on United or American Airlines) I've noticed that if I book directly through an airline over a VPN, I save several hundred bucks versus if I click through from Google Flights or Kayak. Conversely, sometimes GF is less expensive and when I land on the airline's page it's more expensive.
I think the best thing to use it for is route discoverability: which kind of planes and which airlines fly to which locations, on which days at which times? It's also great for doing complex open-jaw routes or hidden-city fares -- and since those routes don't change very often, the data is more likely to be accurate.