I think OkCupid has been doing to POF what Facebook did to MySpace. Mediocre products that serve a real need will survive for a while, but long-term people gravitate towards quality.
That may all end now that they've been acquired by a mega corp though.
I also wonder if there are just limited lifespans for these types of sites. Dating, community (slashdot->kuro5hin->digg->reddit->hn), social networks (friendster->myspace->fb), etc. These sites seem to move in waves like fashion or gentrification.
Even if it wasn't fad driven, there seems to be a significant trend of the number one site getting eclipsed by new up and comers. Whether that trend is coming to a halt with Facebook or not is debatable (they seem to be staying on the leading edge and more than willing to adapt and take in the ideas any competitors would push, along with the most extreme network effect possible).
On the other hand, I doubt that reddit isn't going to suffer the same fate that slashdot and digg did when something better comes along, though I doubt they are going to make as drastic a mistake as digg did.
My guess is googling for "okcupid" all as one word is relatively more frequent than "plentyoffish" as one word, and here's confirmation using Google Insights for Search, which allows OR queries:
Seems naive to think they bought OKCupid just for the revenue. The OKCupid guys were awesome at data mining, visualization, and viral marketing. Their ability to enhance the value of Match.com's existing client base is huge.
Well, PoF just isn't going to get bought. OKC has a special algorithm. PoF is a cheap free copy of dating website ("select users with X miles of Y where gender = Z").
A dating site is more than just an algorithm; its main asset are the users. Match, PoF, etc. have no fancy algorithm, but they are still among the top because of their users. It's the "network effect".
It's curious. Lots of people I know use okcupid; nobody I know uses PoF. The one time I tried joining several years ago, my account was repeatedly deleted. PoF has a target audience, but I have no idea what or where it is. Does anybody?
I was not aware that nobody uses PoF, seems pretty popular to me. I am in Canada (Montreal) though, and this is the first time I've heard that Canada is a PoF niche, so I guess that explains it.
For those who say PoF is an inferior product: with dating sites, it all boils down to 1) number of local users, 2) easy results filtering, 3) easy communication. For me PoF had all three.
OKCupid is already going downhill post acquisition. Friends that are on OKCupid (exes) who were ~70% match earlier, are now ~90% match. It's a shame that OKC tweaked their algorithm just to make a few bucks. Based on their general demeanor, I had assumed they would be above such shenanigans; but it turns out to have been a flawed assumption.
That may all end now that they've been acquired by a mega corp though.
Look at this trend: http://trends.google.com/trends?q=okcupid%2C+plentyoffish...