Contentless RSS feeds

I’ve been using Feedly regularly now and am loving it. Being able to stay up to date with the websites I like without having to follow them on Twitter or Facebook has made me more of a follower than I was.

There are however certain feeds that make it hard for anyone to like them. The Dilbert Daily Strip for example, apart from its weekend comic, the feed only has the following content:

Dilbert readers – Please visit Dilbert.com to read this feature. Due to changes with our feeds, we are now making this RSS feed a link to Dilbert.com.

This is what shows up in my reader everyday. Thankfully, Feedly has an option to open the linked web page directly, which is what I have now done for this feed.

Why do publishers do this? To get more ad impressions? Are ads not allowed on feeds? I’d really love to know the reasons behind this strategy.