Sep 28, 2010 14:17 GMT  ·  By

Twitter's first two advertising products, Promoted Tweets and Promoted Trends have proven rather successful though they are still labeled as experimental. But Twitter is now moving forward with a third option, Promoted Accounts, which is rumored to be announced later today.

Media Memo says the announcement is coming at the IAB conference, an ad industry event in New York, today.

As the name implies, Promoted Accounts enable users, brands or individuals, to pay to have their account featured hoping to increase exposure and follower count.

The Promoted Account will show up next to regular account suggestions in the "Who to Follow" feature, just like Promoted Trends show up next to regular trending topics.

Companies or celebrities who believe in the promotional value of Twitter would pay to have their accounts showcased by Twitter.

The interesting thing is that Twitter supposedly says that Promoted Accounts will show up in the suggestions only if they are relevant to the users' interests, based on who they and their friends are already following.

It is unclear how exactly this "relevancy" will be determined or how strict the limits will be, but the implementation sounds good in theory.

By suggesting only accounts that users may actually find interesting, the engagement rate is likely to be high and the feature will feel more like a useful tool rather than advertising.

Promoted Tweets work in a similar way. These tweets only show up for certain searches for which they are clearly relevant.

However, Promoted Trends are said to be much more popular than Promoted Tweets, and these show up for all users regardless of their interests, more like traditional display ads.

There are no details on how much Promoted Accounts will cost for advertisers or how the success rate will be calculated, either by measuring directly the number of new followers or just from the exposure alone.