As RSS usage has declined so has its value to advertisers, pushing prices down. Less predictable was the big gap between the different kinds of feeds.The feeds sent by Problogger account articles sent to professional Internet users have twice as many subscribers as the feeds. The photography feed though earns ten times as much as the ProBlogger feeds.

Those are two very different kinds of blogs providing very different kinds of content to very different kinds of readers. The people who pick up content about blogging through RSS feeds are going to be fairly sophisticated. They’re used to seeing AdSense units, they’re familiar with them, and they know to ignore them. They’re also looking for information rather than a purchase so the kinds of special offers and products that are likely to appear in the AdSense units are less likely to appeal to them. They’re a much tougher sell.

My photography blog however are enthusiasts willing to make purchases related to their hobby. Because they’re being offered products, and because the ads they see match their desire to buy, those ads get clicks.

That might suggest that feeds that contain content about products will do better than feeds that offer information. But that isn’t necessarily true. Some blog that primarily delivers information rather than product reviews, but it does talk to an audience that’s looking to make purchase a although frugal ones.

There’s no shortage of other publishers though who have reported that they put AdSense in their RSS feeds, saw that it was generating pennies and took it off again. Much will depend on the kind of content you’re sending, and you’ll have to test to see if AdSense for Feeds works for you. But to give the service a chance, you will have to make sure that you set it up right.