Feeds aren't just used for blog entries, though this is what most affiliates use them for because you can use wordpress and a basic parser to get an automatically updated site going.
See this thread for a much more innovative use of RSS technology:
http://www.gofuckyourself.com/showthread.php?t=626095
In a nutshell, we can use a feed to syndicate which webcams.com models are online and associated info for each model so that affiliates can parse the info to have a completely dynamically updated webcam front end.