• by Mark Walsh  @markfwal, February 28, 2012

Twitter said Tuesday it will expand its mobile advertising options in connection with the latest updates to its iPhone and Android apps. With the upgrades, “promoted accounts” and “promoted tweets” will be added to the timeline on its mobile applications for both platforms.

Until now, promoted trends and promoted tweets were available only through a search page when someone accessed Twitter on iPhone or Android or the mobile Web (m.twitter.com). Promoted accounts and promoted tweets have been available on the mobile Web for several months.

“Initially, a small number of users may see Promoted Tweets near the top of their timelines from brands they already follow. This will help people see important Tweets from brands they care about,” stated a Twitter blog post today.

Promoted accounts have been added to Twitter for iPhone and Twitter for Android, with promoted tweets to follow in a few weeks. Both ad products will appear the same as on the Web, with promoted accounts, for example, showing up a user’s list of “Who to Follow” recommendations.

More than half of Twitter’s 100 million monthly users access the microblogging service via mobile, so it’s clearly in the company’s interest to reach that portion of its audience. And with Facebook expected soon to launch its own mobile ad platform, Twitter doesn’t want to get left behind.