Private company

AppNexus

Technology company

AppNexus is an American multinational technology company operating a cloud-based software platform that enables and optimizes programmatic online advertising.3 From Wikipedia, CC BY-SA 4.0

Last updated Oct 16, 2026.

Overview

2007Founded1
  • Industryabrill, ad server, advertising industry, digital display advertising, marketing1
  • HeadquartersNew York City1
  • Websitewww.appnexus.com
  • Incorporated inDE4
  • Business address28 West 23Rd Street, 4Th Floor, New York, Ny 100104

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AppNexus image from its website
Image: appnexus.com5

AppNexus is an American multinational technology company operating a cloud-based software platform that enables and optimizes programmatic online advertising.3

How it started

History

AppNexus was founded in 2007 by former Right Media staff, CTO Brian O'Kelley, and Mike Nolet, product manager and director of analytics. Michael Rubenstein, a former vice president and general manager at Google DoubleClick, who joined AppNexus as president in September 2009. The company was financially backed by Microsoft, Khosla Ventures, First Round Capital, Venrock, Kodiak Venture Partners, Marc Andreessen, Ben Horowitz, and Ron Conway; as of 2015 the company had raised $250 million in financing. O'Kelley stepped down as CEO in October 2018.

From Wikipedia’s article on AppNexus, shared under CC BY-SA 4.0.3

Timeline

  1. 2007Founded Founded1

Sources

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    Company websiteAppNexus photo