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AppNexus is the most advanced platform for buying real-time online advertising. AppNexus's clients include the largest ad networks and online advertisers. AppNexus offers a proprietary gateway to premier ad exchanges and ad inventory aggregators, and cloud computing capabilities for unrivaled scalability. AppNexus is based in New York City.

  • Location

  • news

    AppNexus Buys Yieldex for $100 Million

    Two New York-based startups are merging, with potential IPO ramifications. AppNexus Inc., the automated online advertising technology firm, is acquiring rival Yieldex, the companies are set to announce. The cash-and-stock deal is worth about $100 million.

    April 2, 2015 Wall_Street_Journal

  • news

    For Brian O’Kelley of AppNexus, Learning Never Stops

    Q. Were you an entrepreneur early on?

    A. I was always a failure at lemonade stands, but when I was in high school I was into computers. A buddy of mine and I started building Web sites for local businesses, right when the Internet was taking off in ’95. We eventually had about 50 customers. It was our side project to help pay for pizza in college.

    Q. Sounds like you were busy in college.

    A. At Princeton I got roped into rowing crew. I didn’t really enjoy it all that much. I would row crew at 6 in the morning, go to classes all day, go back and row some more, go to my campus job washing dishes, come home and do my homework and then build Web sites. I would go to sleep at 3 or 4 in the morning, then wake up at 6.

    October 18, 2013 The_New_York_Times

  • news

    New King Of Ad Tech: How AppNexus CEO Brian O'Kelley Went From Fired To First

    Employees at AppNexus, a bustling advertising technology firm near New York City’s peaceful Madison Square Park, don’t often interact with the boss. The five-year-old company, with 547 employees, has been growing too fast for that. Plus, its 6-foot-5, 240-pound CEO, Brian O’Kelley, can be, well, a bit irascible. Office folklore has it that he once threw a stapler at a software engineer. (O’Kelley vehemently denies that version, saying it was a tape dispenser thrown on the floor with no employees present.) And he was forced to resign from his previous job for clashing with the boss and being hard to work for. On a recent Wednesday O’Kelley confessed to FORBES that one of his staffers had earlier that day burst into tears after a project meeting with him. O’Kelley says the tears came from personal issues, “but I was thinking, ‘Oh God, I’m sensitive to my reputation.’ I know the impact I have on people.”

    June 27, 2013 Forbes

  • news

    What It's Like Inside AppNexus' HQ, The Startup That's Rumored To Be The Next $1 Billion Adtech IPO

    One New York tech company that's getting a lot of buzz right now is AppNexus, the online ad platform based in the flatiron district. In January, AppNexus raised a whopping $75 million from Technology Crossover Ventures. Since then it has been on a huge hiring spree, prompting speculation of an IPO in the near future.

    June 24, 2013 Business_Insider

  • news

    Could AppNexus's digital ads be the unlikely saviour of our newspapers?

    Brian O'Kelley is an unlikely saviour of newspapers. For one thing, the 35-year-old chief executive of advertising technology company AppNexus – which has morphed from startup to $1bn behemoth with 500 employees in just five years – concedes he knows very little about print. Digital, however, is his currency and though he will doubtless be accused by some of hyping his company, O'Kelleydescribes saving newspapers as his company's "higher purpose".

    June 18, 2013 The Guardian

  • news

    AppNexus Named OnMedia 100 Company of the Year

    AppNexus is an advertising exchange network that provides clients with a real-time platform to buy and sell online ads. Advertising technology has evolved during the last decade, and AppNexus has consistently provided its clients with a rich back-end suite of tools not only to place advertisements, but manage and pay for campaigns in a highly focused and efficient manner. The demands of today's ad viewers have shifted, and AppNexus has kept pace with how the industry has grown and expanded. 

    March 4, 2013

  • news

    AppNexus Raises $75 Million

    Programmatic ad-buying exchange AppNexus just raised $75 million from TCV.

    That's a lot of money!

    It also makes AppNexus that much less likely to be acquired by Facebook, Yahoo, Microsoft, or Google any time soon.

    It's may be too pricey now. IPO or bust?

    Here's a blog post from CEO Brian O'Kelley:

    I’m excited to announce that AppNexus has closed on a Series D round of $75 million, led by Technology Crossover Ventures (TCV).

    There are so many people to thank – our early investors (especially Ben, Marc, Ron, and Josh), our mentors and advisors (especially David and Dwight), and our board (Brian, Ed, Mike, Dave, and Chip). I also want to thank all of the clients and partners who have helped us build the company and continue to trust us with their business. It’s a responsibility and privilege we don’t take lightly. 

    January 24, 2013 Business_Insider

  • news

    AppNexus CEO to Potential Investors: We Don't Need Your Money

    These days, there always seems to be one rumor or another about AppNexus, the ad-exchange startup run by former Right Media chief technology officer Brian O'Kelley. The New York City-based company, which had 288 employees as of earlier this week and sees 27 billion ad impressions run through its platform daily, is either trying to raise a huge round of funding or trying to go public depending on who you ask and on what day.

    July 27, 2012 AdvertisingAge

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    CEO Says AppNexus Sales are Growing 150 Percent a Year (Video)

    Brian O'Kelley, chief executive officer of AppNexus, talks about the company's growth. O'Kelley also discusses the possibility that Yahoo! Inc. may outsource its display advertisements to AppNexus. He speaks with Jon Erlichman on Bloomberg Television's "Bloomberg West."

    April 26, 2012 BusinessWeek

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    Looking To Lead, AppNexus Fuels Startups, Adds Apps And RTB For Video Ads

    Some of the best events related to ad technology are produced by vendors and The AppNexus Summit is one of those as it draws a strong, global crowd of entrepreneurial ad tech types who are ready to listen to what is ultimately a compelling, well-crafted sales pitch for the AppNexus platform. Above all, the event sought to establish, if not cement, a leadership position for AppNexus in the world of digital, audience buying.

    April 5, 2012 AdExchanger

  • news Co-Founder Atherton Joins AppNexus

    Mr. Atherton will open a San Francisco office for AppNexus and be responsible for "deepening AppNexus' relationships with strategic accounts across the online-advertising ecosystem," according to a statement.

    April 3, 2012 Advertising_Age

  • video

    Introducing AppNexus Apps

    January 27, 2012

  • news

    Web advertising's master auctioneers

    When you visit just about any website these days, ads appear as the site loads. But what you can't see is that many of those ads were not predestined for your eyes-- advertisers won the spots in near-instantaneous auctions occurring in the quarter of a second between click and use of the site.

    January 5, 2012 Fortune

  • video

    AppNexus Summit NYC 2011 Opening Remarks

    December 6, 2011

  • news

    Inside One Of New York's Greatest Startup Success Stories, AppNexus

    Last week we went to visit one of the biggest startups in New York, AppNexus. AppNexus was founded in 2007 by Brian O'Kelley and Mike Nolet. Both were early members of ad exchange Right Media, which sold to Yahoo at an $850 million valuation in 2007.

    November 3, 2011 Business_Insider

  • news

    Google Competitor AppNexus Grabs Another Googler (By Way of Nielsen)

    AppNexus, the start-up that's trying to help Microsoft build a competitor to Google's display advertising business, has added another Googler to its team.

    March 28, 2011 All_Things_D

  • news

    Paparo Joins AppNexus; Discusses New Product Leadership Role

    Ari Paparo has moved to real-time ad platform AppNexus to become their senior vice president of product management. According to the release, Paparo “brings over 10 years of experience overseeing the development of the industry's leading advertising technology platforms at Google, DoubleClick, and Nielsen.” 

    March 28, 2011 AdExchanger

  • news

    AppNexus Makes Advertising More Personal, Profitable

    Once reliant on mass appeal to win over consumers, advertising has become a more personal experience in the internet age. And the real-time ad platforms like those provided by New York-based AppNexus will turn advertising into an increasingly intimate business. CEO Brian O'Kelley explains why this future shouldn't be feared.

    March 11, 2011 Scribemedia

  • news

    Microsoft Takes Another Stab at Selling Its Own Ads–By Getting Someone Else to Do It

    It's about time! Or, more accurately, “real time”: It's taken Microsoft several years to get its head around the idea, but the company is finally going to start selling its ad space via a “real-time bidding” exchange, just as Google does.

    January 31, 2011 All Things D

  • news

    You Don't Have to Reinvent the Wheel

    Investment banking firm GCA Savvian recently calculated that venture capitalists (VCs) have poured $2.5 billion into the online display space in the past three years. It's a phenomenal bet, but maybe not when you consider the large numbers we've seen in the headlines of late. Just a week ago, the Interactive Advertising Bureau announced that U.S. Internet advertising revenues hit $6.4 billion in Q3 2010, representing the highest quarterly result ever for the online advertising industry and a 17 percent increase from the same period in 2009. The Wall Street Journal reported in November that the online advertising market "is expected to total roughly $20 billion world-wide this year." Some are now predicting this market may grow to $50 billion over the next few years.

    December 7, 2010 Clickz

  • news

    O'Kelley Says AppNexus Growing Fast, "Hiring Like Crazy" (Video)

    Brian O'Kelley, chief executive officer of AppNexus, discusses the outlook for the online real-time display ad-bidding company. O'Kelley speaks with Deirdre Bolton on Bloomberg Television's “InsideTrack.” 

    October 22, 2010 Mefeedia

  • news

    AppNexus Raises A Meaty $50 Million Series C For Realtime Ad Bidding Platform

    Realtime ad bidding network AppNexus today announced that it raised $50 million in a Series C financing. Investors include Microsoft, Venrock, Kodiak Venture Partners and First Round Capital. The round brings the total capital raised by AppNexus since its founding to $65.5 million. The company first raised an angel round in 2007 from Ron Conway, Marc Andreesen, Ben Horowitz, Khosla Ventures, and First Round Capital.

    October 5, 2010 Techcrunch

  • investment

    Received $50M Series C Funding

    Participation Microsoft, Venrock, and First Round Capital

    October 1, 2010

  • news

    AppNexus Expands Real-time Bidding Globally With New Data Center in the Netherlands

    AppNexus, the real-time ad platform, today announced that it has opened its first data center outside North America -- in Amsterdam, the Netherlands -- a move which significantly expands the opportunity for real-time bidding (RTB) in Europe and the Middle East in response to rising demand among global ad networks, demand-side platforms (DSPs) and other online advertising companies in those regions. 

    September 29, 2010 prnewswire

  • news

    AppNexus Hosts Its Inaugural 'What Works' Summit on Online Advertising

    AppNexus, the real-time ad platform company, is hosting its first 'What Works' Summit ( at the Four Seasons Hotel in San Francisco today from 8:00 am to 1:00 pm in connection with the conclusion of ad:tech San Francisco. This inaugural AppNexus Summit will focus on the evolution of ad networks and aggregators in the new display advertising landscape especially in relation to real-time bidding, and will bring together industry leaders to discuss what really works to drive results, build enterprise value, and meet new challenges. The event is sponsored by 24/7 Real Media, Media Innovation Group, AdMeld and Netezza.

    April 22, 2010 prnewswire

  • news

    AppNexus Is A Real-Time Ad Platform – The On-Ramp For Companies Like DSPs Says CEO O'Kelley

    BOK: Yes, we've been extremely busy at AppNexus commercializing our ad platform with some of the most sophisticated online marketers, ad networks and DSPs in the business. Growing a successful start-up of course also means building up a team of the best and the brightest, and we've been able to recruit some serious talent over the past few months. We recently announced that Lauren Nemeth from Google joined us as Director of Sales and Timothy G. Smith from Vonage joined as our Vice President of Technical Operations. They are huge wins for us and we're delighted to have them on board. We will be making more personnel announcements in the near future, but we also want the industry to know that we're still hiring, and looking to bring on more superstars across the board, including sales, client services, engineering and marketing.

    April 1, 2010 AdExchanger

  • news

    AppNexus Makes Key Additions to Leadership Team With Technology and Sales Hires From Google and Vonage

    AppNexus, the real-time ad platform, today announced that it has hired advertising industry veteran Lauren Nemeth as Director of Sales and seasoned technology expert Timothy G. Smith as Vice President of Technical Operations. Founded and managed by the pioneers of the Web's original and most successful ad exchanges at Yahoo!'s Right Media and Google's DoubleClick, AppNexus offers unparalleled, highly scalable technology, deep industry expertise and plays host to a vibrant community of leading companies within the online advertising ecosystem. 

    March 30, 2010 prnewswire

  • news

    The 20 Hot New York City Startups You Need To Watch

    The New York digital scene has had a major renaissance in recent years.

    March 18, 2010 Business_Insider

  • news

    AppNexus Officially Launches Ad Platform Fueling the Real-Time Bidding Revolution in Display Advertising

    AppNexus today announced the launch of its advanced ad platform specializing in real-time advertising ( Founded and managed by the pioneers of the Web's original and most successful ad exchanges at Yahoo!'s Right Media and Google's DoubleClick, AppNexus offers unparalleled, highly scalable technology, deep industry expertise and plays host to a vibrant community of leading companies within the online advertising ecosystem. Chosen by eBay, the Web's premier online marketer, as its display advertising technology partner, the AppNexus platform integrates eBay with all the major inventory sources to execute and optimize its real-time media buys.

    March 12, 2010 prnewswire

  • news

    Instant Ads Set the Pace on the Web

    Advertisers have been able to direct online messages based on demographics, income and even location, but one element has been largely missing until recently: immediacy. Advertisers booked slots in advance, and could not make on-the-fly decisions about what ads to show based on what people were doing on the Web.

    March 11, 2010 The_New_York_Times

  • investment

    Received $5M Series B Funding

    Participation Kodiak Venture Partners, Venrock, First Round Capital

    November 1, 2009

  • investment

    Received $8M Series B Funding

    Participation First Round Capital, Khosla Ventures, Kodiak Venture Partners, Venrock

    September 1, 2008

  • investment

    Received $2.5M Angel Funding

    Participation First Round Capital, Khosla Ventures, Marc Andreessen, Ron Conway, Ben Horowitz, Coriolis Ventures

    December 1, 2007