RSS feeds and blogs represent a seldom-used opportunity for publishers to better monetize their content. A year or two ago, there was debate over whether advertising in feeds was viable and, if so, if it was it worth it or would it repel subscribers? These questions are moot today, as subscriber resistance has been minimal and an increasing number of advertisers are inserting their messages into RSS feeds. Additionally, Google's entrance into the marketplace helped validate the model when it acquired Feedburner last month. Feedburner, as well as Pheedo, provides enabling technologies for advertisers to insert their feed into outside RSS feeds. They also represent a network of sites with RSS feeds that can be bought by advertisers, which allows advertisers to dynamically insert both text and graphics into the network of feeds.

Targeting, for the most part, can be done contextually by category of sites. The most effective RSS advertising is related to the feed's content and is content-driven. Another advantage to RSS feed advertising is the relative lack of clutter, although as RSS advertising increases in popularity that is sure to change.

RSS advertising analytics are also becoming more sophisticated. Most of the vendors allow advertisers to not only track clickthrough rates but other types of engagement triggers as well, including sharing with friends, Digg(ing), adding to del.icio.us, Technorati submissions and subscriptions to a feed. CPM rate cards range from approximately $5 to $15 for B2C-focused feeds and $15 to $50 for B2B-focused feeds, depending on the degree of targeting. RSS feed advertising presents the best opportunity to advertisers that generate content themselves, including travel, automotive and entertainment sites.

Examples include:
FeedBurner (acquired by Google)
Google AdSense (in Beta)
Pheedo