MinnPost, the non-profit news startup in Minneapolis, has rolled out a new form of advertising. Called Real-Time Ads, the ad unit shows headlines and links to Web sites in a skyscraper box that looks like a display ad but with real time updating ala Twitter. It’s live in the left hand column of the home page of MinnPost.com.

The service aggregates tweets, blog posts, and other feeds from local business. Three ads are randomly served. The ads rotate every time a reader goes to a new page on the site. The service can accommodate a maximum of 32 ads. There’s an option to view all ads.

The MinnPost site describes the ads like this:

“For a modest weekly charge, you can show MinnPost’s readers the headlines or brief summaries of these messages you’re already creating, and watch them link to your full messages on your website.”

Real-Time Ads are free now as the service is in beta. Plans are to charge under $100 a week – a different model than the $15 per thousand impressions MinnPost charges for display ads. The ads are for local businesses and are only served to readers in Minnesota.

There’s an interview with MinnPost editor Joel Kramer on the Nieman Lab Web site.