Twitter's ad world just got a little bigger.
The messaging service -- whose business is already 75% mobile -- started selling ads in mobile apps beyond Twitter today, a key rationale of its purchase of MoPub, a mobile ad exchange it purchased in September.
MoPub will allow Twitter's advertisers to buy mobile app install ads through the exchange. App install ads are today the mobile web's dominant form of advertising and a key source of revenue for Facebook and other publishers.
Via the integration, advertisers can buy mobile app install and app engagement ads on Twitter, as well as on the thousands of apps within MoPub's network, which include WordPress, OpenTable, the mobile messaging app Tango, and the music-streaming app Songza.
Twitter's intention to launch mobile app install ads has been a poorly kept secret. Promoted tweets with Twitter "Cards" attached in which users can click to install an app have been materializing in users' Twitter streams over the last few weeks.
Though still in a private beta, mobile app install ads will be available for purchase in Twitter's ad auction, and other targeting parameters can be applied to them. But separately, advertisers will be able to participate in real-time bidding to buy mobile app install and app engagement ad inventory programmatically via MoPub within the Twitter ad system. Those ads will appear as banners, interstitials, video and sometimes in native formats.
MoPub works with various demand side platforms, or programmatic buy-side technologies, receiving 130 billion ad requests per month, and Twitter will now be effectively one of them. An important distinction, however, is that Twitter's own inventory is not being opened up to programmatic buying.
"This is an easy way for Twitter marketers and mobile app developers to extend the campaigns that they're running on Twitter across the rest of the mobile ecosystem through MoPub's exchange," said Kevin Weil, the company's VP-product for revenue.
Early beta partners buying app install ads via the so-called "Twitter publisher network" include Spotify, HotelTonight, Kabam, Deezer, SeatGeek, GREE and GetTaxi.
Twitter reported revenue of $242.7 million for the fourth quarter of last year, up 116% from $112 million over the previous year. That amounted to a profit of $9.8 million on an adjusted basis.