According to a just-published report by ClickZ, Twitter is realizing a significant bit of revenue from auto advertising.  Twitter CRO Adam Bain told  ClickZ that in Q1 of 2011 twelve percent of its revenue came from auto marketers.  Most popular is Twitter’s Promoted Accounts program.

“Promoted accounts are one of the best hidden secrets of the platform,” Bain said. “Unlike trends, they’re based on targeting. If the marketer understands the value of a certain type of customer, they can bid really effectively. “Each marketer knows how much a follower is worth to them, and once they’ve acquired that follower, brands can keep marketing to them.”

While the average auction price that advertisers pay Twitter for each follower is around $10, auto advertisers have paid up to $70.  These advertisers seem happy with Twitter, as 80 percent of them come back time and again.   Nissan, Volkswagen and Mercedes are the most prominent repeat advertisers.

Here’s the whole story from ClickZ.