Although intrigued, mainstream advertisers are for the most part staying away from RSS ads. The problem (just as with any emerging media buy) is reach. Tests aren't worth the work unless you have a significant population to roll your campaign out to if the test wins.

However, now that Google's started putting AdSense ads into RSS feeds, and major news sites such as USAToday.com and NYTimes.com are seeing double-digit monthly leaps in RSS-usership, we bet reach won't be a problem by 2006.

Interested? Check out our exclusive behind-the-scenes look at how Citrix's GoToMeeting just tested RSS and Podcasting ads:

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