Yahoo has partnered with Media.net to launch an ad network for Web publishers that will compete against Google's AdSense and similar services.
The service, called Yahoo Bing Network Contextual Ads, will place ads on the websites of participating publishers, choosing the ads based on the context of the Web pages.
Media.net will be in charge of the technology, business operations and relationships with publishers, while Yahoo will do the same for advertisers, the companies said Thursday.
The service is aimed at websites that publish premium content and, for now, that get most of their traffic from the U.S., Canada and the U.K.
According to the companies, publishers can start running ads "in minutes" via the self-serve platform, which gives them options about the size and "skin" of the ads.
Through the use of keywords, publishers can influence the ads the service picks for any particular Web page, and they can also block certain ads and topics from appearing on their websites.
The ads from the Yahoo-Media.net network can be run alongside ads from other providers, and they can also be optimized for iOS, Android and BlackBerry mobile devices.
Participation in the service also includes service support for publishers.
Yahoo, which generates most of its revenue from online advertising, has been floundering in this market. A wide-ranging, 10-year deal with Microsoft for search advertising signed in 2009 struggled out of the gate and hasn't come close to fulfilling its goal of challenging Google's dominance. Meanwhile, Yahoo's position in display advertising, where it had historically been a leader, has been weakening in recent years, losing ground to Google and Facebook.
In April 2010, Yahoo closed an ad network for small Web publishers, saying that the service had failed to gain enough traction in its five years of operation.
That service, called the Yahoo Publisher Network, provided pay-per-click test ads to participating publishers, which ran primarily lower-traffic websites, such individual blogs.