Every time a page loads, an auction can happen before the ad appears, and Rubicon Project ran those auctions for websites. The Los Angeles company built software that let publishers offer each ad slot to many buyers at once and sell it to the highest bid in a fraction of a second. When it went public in April 2014, most ad tech companies worked for advertisers. Rubicon worked for the sellers.

Working for the Publisher

Frank Addante and Craig Roah founded Rubicon Project in 2007. Addante had founded ad companies before, including L90. Their idea was an automated exchange that let a publisher put each ad impression up for auction to many demand sources at once. Rubicon took a cut of each sale. The bet was that as ad buying moved to machines, publishers would need their own machine to get a fair price.

From Rubicon to Magnite

Rubicon Project priced its IPO at $15 a share in April 2014 on the New York Stock Exchange. Growth stalled a few years later as fees fell across the industry and Google's tools grew stronger. In 2020 Rubicon merged with Telaria, a video ad company, and renamed itself Magnite. It then bought SpotX and SpringServe to build a large business in streaming TV ads. Magnite trades on Nasdaq under MGNI.

Cover: Crossing the River at Sano, Okumura Masanobu. Art Institute of Chicago, public domain. Chosen for crossing a river (the Rubicon).