Estimated Value: $80 million

Last Year's Valuation: N/A

Business:  Network of question and answer sites

Location: New York, NY

More Info: About Stack Exchange

CEO: Joel Spolsky

Investors: Union Square Ventures, Index Ventures, and Spark Capital

Analysis: Stack Exchange is a network of Q&A sites.  It raised $12 million in March 2011. We estimate the company's value is about $75 million. 

Estimated Value: $100 million

Last Year's Valuation: N/A

Business: Financial tools and content for women

Location: New York, New York

More Info: About LearnVest

CEO: Alexa von Tobel

Investors: Richmond Management, Rose Tech Ventures, Circle Financial Group, PKS Capital, Accel Partners, Circle Financial Group.

Analysis: LearnVest is a financial tools, services, and content company. It is positioning itself to become a Mint.com for the female set. 

LearnVest's business closely resembles Investools, which was acquired by TD Ameritrade for an estimated $600 million. Mint.com was acquired by Intuit for $170 million while generating $6 million in annual revenue. 

In July, LearnVest raised a $19 million round, bringing its total funding to $24.5 million. It's seeing quick adoption among advertisers and users, and conversion rates on its recently launched subscription product are exceeding expectations. We estimate a $100 million valuation.

Estimated Value: $100 million

Last Year's Valuation: $100 million

Business: Clean Technology

Location: New York, New York

More Info: About RecycleBank

CEO: Jonathan Hsu

Investors: Generation Investment Management, Paul Capital Investments, RRE Ventures, Sigma Partners, Kleiner Perkins Caufield & Byers and The Westly Group

Analysis: RecycleBank partners with cities and haulers to reward households for recycling. Households then earn RecycleBank Points that can be used to shop at participating businesses. Last year, we estimate the company generated about $9 million in revenue. We assume revenue doubled this year and apply a 5X multiple, for a valuation of $100 million.

Estimated Value: $100 million

Last Year's Valuation: N/A

Business: SEM Software

Location: New York, NY

More Info: About Clickable

CEO: David Kidder

Investors: FirstMark Capital,Union Square Ventures, and Founders Fund

Analysis: Clickable is a complete PPC management solutions company for advertisers. It has raised $20.5 million to date and revenue is up 200% YoY. Sources close to the company say Clickable's valuation is about $100 million.

Estimated Value: $100 million

Last Year's Valuation: $90 Million

Business: Social and e-mail acquisition platform

Location: Brooklyn, New York

More Info:  About Pontiflex

CEO: Zephrin Lasker

Investors: New Atlantic Ventures, Greenhill SAVP, RRE Ventures

Analysis: Pontiflex aims to help advertisers reach digital media users with ads that prompt user sign ups. It launched a mobile advertising service this year which is growing rapidly.

Pontiflex raised $6 million in February 2011; we estimate it will generate $20 million in revenue this year, up from $12 million last year. We apply a 5X multiple on revenue for $100 million valuation.

Estimated Value: $105 million

Last Year's Valuation: $100 million

Business: eCommerce

Location: New York, New York

More Info: About Rent The Runway

CEO: Jennifer Hyman

Investors: Bain Capital Ventures, Highland Capital, and Kleiner Perkins Caufield & Byers

Analysis: Rent The Runway allows users to rent dresses for a fraction of the cost of buying the dress outright. We estimate that Rent the Runway will generate about $20 million of revenue in 2011, up from $6 million in 2010.  We value the company at $105 million, about a 4X multiple of revenue.

Estimated Value: $120 million

Last Year's Valuation: N/A

Business: Warby Parker is a prescription glasses online discount retailer.

Location: New York, New York

More Info: About Warby Parker

Co-CEO: Neil Blumenthal and Dave Gilboa

Investors: First Round Capital, SV Angel, Lerer Ventures, Davis Smith.

Analysis: While margins for online retailers aren't huge, glasses are something that are purchased almost annually; Warby's product inherently encourages repeat customers.  One of the sources estimates that Warby Parker has already sold more than 100,000 pairs of glasses in the last year.

Two sources involved in the financing and one additional industry source say that the $12 million round Warby Parker just raised was at an estimated valuation of $100-200 million.

Estimated Value: $130 million

Last Year's Valuation: #78 / $150 million

Business: Social network and community for moms

Location: New York, New York

More Info: About CafeMom

CEO: Michael Sanchez

Investors: Highland Capital Partners and Draper Fisher Jurvetson

Analysis: CafeMom is the ever-popular social network for moms, where women come together to get advice and support on various topics. We estimate that CafeMom will generate about $35 million of revenue in 2011, up from $30 in 2010.  We value the company at $130 million, a 3-4X multiple of revenue.

Estimated Valuation: $140 million

Last Year's Rank / Valuation: N/A

Business: Multi-platform media company aimed at men

Location: New York, NY

More Info: About Complex

CEO: Rich Antoniello

Investors: Accel Partners and Austin Ventures

Analysis: We estimate that Complex Media will generate about $35 million of revenue this year, up from $20-25 million in 2010.  At a 4x multiple of revenue, we estimate Complex Media's valuation is $140 million.

Estimated Value: $150 million

Last Year's Valuation:  $75 million

Business: Online Newsletter Service

Location: New York, New York

More Info: About Thrillist

CEO: Ben Lerer

Investors: NA

Analysis: Thrillist is a digital lifestyle publication, currently reaching over 2 million subscribers in 17 markets. It has recently seen a lot of success with a daily deals feature, which has been rapidly generating revenue for the startup.

We estimate that the company is on track to generate about $40 million of revenue this year, up from $10-15 million last year. It's commerce business has been growing steadily, so we estimate half of the revenue at a 5X multiple and the other half at a 2-3X multiple for a $150 million valuation.

Estimated Value: $150 million

Last Year's Valuation: N/A

Business: Socially targeted advertising platform

Location: New York, NY

More Info: About Media6Degrees

CEO: Tom Phillips

Investors: Menlo Ventures, US Venture Partners, and Venrock

Analysis: Media6Degrees is an advertising network that specializes in social targeting. We estimate that Media6Degrees' revenue will generate about $30 million of revenue this year, up from $20 million in 2010. We value the company at $150 million, a 5X multiple of revenue.

Estimated Value:  $175 million

Last Year's Valuation: $150 Million

Business: Online media company

Location: New York, New York

More Info: About Gawker Media 

CEO: Nick Denton 

Investors: Self-funded

Analysis: Gawker Media is an online media network. We estimate that the company will generate about $30 million of revenue this year. Applying a 6X multiple, we estimate a valuation of about $175 million.

Estimated Value: $175 million

Last Year's Valuation: $275 million

Business: Contextual / In-text ad network

Location: New York, New York

More Info: About Vibrant Media

CEO: Jeff Babka

Investors: Fortis, ABS Ventures

Analysis: Vibrant media is a contextual (in-text hyperlinking) advertising company.

We estimate that Vibrant will generate about $130 million of revenue in 2011, flat from the year prior.  We value the company at $175 million, a 1-2X multiple of revenue.

Estimated Value: $175 Million

Last Year's Valuation: N/A

Business: Offers a platform for buying real-time online advertising.

Location: New York, NY

More Info: About Appnexus

CEO: Brian O'Kelley

Investors: Venrock, Kodiak Venture Partners, First Round Capital, and Microsoft

Analysis:  Appnexus is an advanced ad platform specializing in real-time auction bidding.  We estimate that the company will generate around $25 million in 2011 revenue, up from $7 million in 2010.  Applying a 7x multiple on 2011 revenue, we estimate Appnexus's value to be $175 million. 

Estimated Value: $200 million

Last Year's Rank / Valuation: $250 million

Business: Online marketplace for illiquid assets

Location:  New York, New York

More Info: About SecondMarket

CEO: Barry Silbert

Investors: FirstMark Capital, Li Ka-Shing, Temasek

Analysis:  Second Market made a lot of news in 2011 by brokering privately held shares of companies likes Facebook, Twitter, and LinkedIn.  The company also trades in bankruptcy claims, convertible debt, and various forms of illiquid assets. 

We estimate that SecondMarket will generate about $35 million of revenue in 2011, up from $16 million in 2010. We use a 6x multiple on revenue to get a $200 million valuation.

Estimated Value: $200 million

Last Year's Valuation: N/A

Business:  Quick patient check-in device

Location: New York, NY

More Info: About Phreesia

CEO: Chaim Indig

Investors: HLM Venture Partners, Long River Ventures, Polaris Venture Partners, BlueCross BlueShield Venture Partners, Sandbox Industries, Adcension Health Ventures

Analysis: Phreesia is a quick patient check-in device used by doctors offices.  It raised $20 million last summer, bringing its total financing to $42 million. The company generates revenue via pharmaceutical advertising. We estimate the company's value is about $200 million.

Estimated Value: $200 million

Last Year's Rank / Valuation: $250 million

Business: Ad network, digital media buying

Location: New York, New York

More Info: About Undertone

CEO: Michael Cassidy

Investors: JMI Equity, ORIX Venture Finance

Analysis: Undertone is a high-end interactive ad network, specializing in display ads and video.  We estimate the company will generate about $125 million in revenue in 2011; up from just under $100 million last year. We apply a 1-2x multiple on revenue and get an estimated a valuation of $200 million.

Estimated Value: $225 million

Last Year's Rank / Valuation: $175 million

Business: Online video ad network

Location: New York, New York

More Info: About Tremor Video

CEO: Bill Day

Investors: Canaan Partners, Masthead Venture Partners, European Founders Fund, Meritech Capital Partners, SAP Ventures, Draper Fisher Jurvetson, Tirangle Peak Partners, DFJ Growth

Analysis: Tremor Video is a video advertising network that provides streaming video advertising on the web.  We estimate it will generate about $100 million in 2011 revenue, up from $75 million last year.  On a 2x revenue multiple, we estimate the company's valuation at $225 million.

Estimated Value: $225 million

Last Year’s Rank / Valuation: $800 million

Business: A subscription-based job search and recruiting site for positions paying $100K+

Location: New York, New York

More Info: About TheLadders.com

CEO: Marc Cenedella

Investors: Matrix Partners and Roger Ehrenberg

Analysis: TheLadders shares recently traded at a valuation of about $225 million on Sharespost.

Estimated Value: $225 million

Last Year's Rank / Valuation: $300 million

Business: A site dedicated to buying and selling homemade and handmade goods ("eBay for arts and crafts").

Location: Brooklyn, New York

More Info: About Etsy

CEO: Rob Kalin

Investors: Caterina Fake, Stewart Butterfield, Joshua Schachter, Albert Wenger, Union Square Ventures, Accel Partners, Hubert Burda Media

Analysis: We estimate that Etsy will generate about $75 million of revenue this year, up from $50 million in 2010.  We apply a 3x multiple on revenue and estimate a value of $225 million.

Estimated Value: $275 million

Last Year's Valuation: N/A

Business: Provides display advertising solutions for advertisers and publishers.

Location: New York, NY

More Info: About Collective

CEO: Joe Apprendi

Investors: Accel Partners, Greycroft, iNovia Capital

Analysis:  Collective is a platform for digital display advertising.  We estimate the company will generate about $150 million in revenue in 2011, up from $100 million in 2010.  At a 2X multiple of revenue, we estimate a $275 million valuation. 

Estimated Value: $350 million

Last Year's Rank / Valuation: $300 million

Business:  Online grocer

Location:  Long Island City, New York

More Info: About FreshDirect

CEO: Rick Braddock

Investors: Wm Morrison Supermarkets, AIG Global Investment Corp, AIG Capital Partners, Maverick Capital, CIBC Capital Partners, Canyon Partners, Mercantile Capital Partners

Analysis:  Fresh Direct is the online grocer that delivers to your house, while putting a premium on customer service.  Fresh Direct raised $50 million from UK based grocery chain Wm Morrison Supermarkets, in March of 2011. 

With $350 million in estimated 2011 revenue, we use a 1X to estimate a $350 million valuation.

Estimated Value: $350 million

Last Year's Rank / Valuation: $250 million

Business:  Online retail

Location:  New York, New York

More Info: About ideeli

CEO: Paul Hurley

Investors: $41 million in 2011 funding came from Next World Capital, Cue Ball Capital, StarVest Partners, Constellation Growth Capital and Kodiak Venture Partners.

Analysis: Ideeli is an online discount retailer specializing in fashion, beauty, home, and travel deals.  Their items are not available for long and, as such, Ideeli falls under the "flash sales" category. 

We estimate that ideeli will generate about $250 million of revenue this year.  At a 1-2x multiple of revenue, we estimate Ideeli's valuation at $350 million. 

Estimated Value: $400 Million

Last Year's Rank / Valuation: $480 million

Business: Online health information resource

Location: New York, New York

More Info:  About Everyday Health

CEO: Benjamin Wolin

Investors: Foundation Capital, NeoCarta Ventures, Revolution, Rho Ventures, Scale Venture Partners, Village Ventures

Analysis: Everyday Health is a resource for health information, including a personalized option; it's a bigger, better WebMD. The company canceled IPO plans in late 2010 and raised a $20 million round instead.

We estimate that the company will generate about $100 million of revenue this year.  Applying a 4X multiple, we get a valuation of $400 million.

Estimated Value: $400 million

Last Year's Rank / Valuation: $250 million

Business: SEM agency for local businesses

Location: New York, New York

More Info: About Yodle

CEO: Court Cunningham

Investors: Bessemer Venture Partners, Draper Fisher Jurvetson, Wharton Venture Initiation Program, Mento Tech Ventures, Draper Fisher Jurveston Growth Fund, and JAFCO Ventures

Analysis: Yodle specializes in helping local businesses market themselves on the web. We estimate revenues will reach $100 million this year, up from about $70 million in 2010. We apply a 4x multiple to revenue and reach a valuation of $400 million.

Estimated Value: $500 million

Last Year's Rank / Valuation: $150 million

Business: Social media management platform

Location: New York, New York

More Info: About Buddy Media

CEO: Michael M. Lazerow

Investors: Institutional Ventures, GGV Capital, Roger Ehrenberg, Softbank Capital, European Founders Fund, Greycroft Partners, Ron Conway, and Bay Partners.  The most recent round of funding came in June of 2011; Buddy Media raised $54 million to accelerate growth.

Analysis: 2011 was a good year for Buddy Media.*  We estimate that the social media management platform for brands is on pace to double yearly revenue this year, reaching an estimated $20 million. An August funding round valued the company at about $500 million.

*Disclosure: Buddy Media is a sponsor of the Digital 100 list.

Estimated Value: $600 million

Last Year's Rank / Valuation: $100 million

Business: Location-based social network 

Location: New York, New York 

More Info: About Foursquare

CEO: Dennis Crowley 

Investors: Union Square Ventures, O’Reiley AlphaTech Ventures, Jack Dorsey, Kevin Rose, Alex Rainert, Ron Conway, Joshua Schachter Chad Stoller, Sergio Salvatore, Andreessen Horowitz.  The most recent round of funding occurred in June of 2011.  The company raised $50 million.

Analysis: Foursquare is a ___location-based social networking service.  2011 has been a big year for the company, having inked partnership deals with companies like American Express and ESPN and achieving total registered users of 10 million. The company also recently clocked its one-billionth check-in.  A $50 million funding round in June of this year valued the company at $600 million.

Estimated Value: $700 million

Last Year's Rank / Valuation: N/A

Business: Online booking for doctor and dentist appointments

Location: New York, NY

More Info: About ZocDoc

CEO: Cyrus Massoumi

Investors: Jeff Bezos, DST Global, The Founders Fund, Khosla Ventures, Mark Benioff, and SV Angel

Analysis: ZocDoc is an easy way to book last-minute doctor appointments online. It is used by more than 700,000 people per month. ZocDoc is free for patients and charges every featured practice $250 per doctor.

This summer, DST Global invested $50 million in ZocDoc at about a $700 million valuation.

Estimated Value: $800 million

Last Year's Valuation: N/A

Business: Blog hosting platform

Location: New York, NY

More Info: About Tumblr

CEO: David Karp

Investors: Union Square Ventures. Spark Capital, Sequoia Capital and reportedly, Greylock Partners

Analysis: Tumblr's traffic exploded this year, and so did their valuation. New York-based blogging platform Tumblr is talking to fancy venture capital firms about raising another huge pile of cash at a very generous valuation.

Tumblr is in talks to raise $75 million to $100 million at a valuation "in the range" of $800 million – possibly higher.

Estimated Value: $1.05 billion

Last Year’s Valuation: $750 million

Business: Online private sales of luxury and fashion brands

Location: New York, New York

More Info: About Gilt Groupe

CEO: Kevin Ryan

Investors: The New York-based company has raised more than $80 million of capital in several rounds from Matrix, General Atlantic, and others. In February it raised $80-$100 million from private-market investors.

Analysis: Gilt takes excess inventory of luxury goods and sells them on a members-only, by-invitation-only e-commerce site. The company is well-funded and has a management team with a lot of industry experience. We think e-commerce will continue to gain share of the overall U.S. retail market, which bodes well for sites like Gilt.

Gilt booked about $270 million in revenue in the fiscal year ending June 2010, and its revenue should have approached $500 million this fiscal year.

The 2011 Digital 100: The Most Valuable Private Tech Companies In The World >>