Twitter announced February 29th that mobile ads will start rolling out for its iPhone and Android apps starting this week. Promoted tweets will now appear in mobile users’ feeds (just like a regular tweets) and promoted accounts will appear in the app’s “who to follow” section. This is in addition to the promoted trends and promoted tweets that have appeared when searching in the app since fall of last year, as well as promoted tweets already appearing for users of the HTML5-enabled mobile site (m.twitter.com). This move is key to reaching the full potential of audience for Twitter ads, since 55% of monthly active users access Twitter through mobile phones.
Because inventory for all ads—desktop and mobile—is the same and because advertisers can’t target mobile users specifically, there is no additional cost to serving ads to iPhone and Android users. They will initially appear only on Twitter’s official app, so they won’t affect third-party apps like Echofon and UberSocial—at least until more debate and possible negotiations with these providers pan out.