If you're a fan of Pandora -- the wildly popular online music service -- then get ready for a new slate of advertising on the site. And while that may not be the best of news for Pandora fans -- who like their music stations ad free -- the new marketing messages are designed to hit a more targeted local audience. Pandora is working with Seattle-based AdReady to create a new display advertising platform by which small advertisers -- bands, summer festivals or local shops -- can get their messages out to Pandora listeners.

After nearly hitting the wall last year, Pandora is aggressively looking at ways to monetize its fast-growing audience. The online radio station had about 40 million registered users at the end of last year, with the company saying that it planned to reach profitability in 2010.

One way to do that it is by adding more effective advertising from smaller advertisers, a place where AdReady thinks it can help. For example, one could imagine summer music festivals like Sasquatch or Bumbershoot placing ads on Pandora to promote their events when a listener chose one of the artists who planned to perform.

AdReady -- which also counts Yahoo, ESPN and The New York Times as clients -- is backed by Bain Capital Ventures, Khosla Ventures and Madrona Venture Group. It was founded in 2006 by former Classmates.com executive Aaron Finn.

"Pandora is transforming the way people access and listen to music. Advertisers that have usually been relegated to buying traditional advertising can now be a part of that revolution," said Finn in today's release.

John Cook is co-founder of TechFlash. Follow on Twitter @johnhcook.