There's a debate rumbling in the blogosphere right now about whether advertising in RSS feeds is a good or bad thing. At the end of the day, users will decide because they can unsubscribe to feeds they think are abusing their loyalty. Dave Winer (50) summarises my advice to businesses very well:

Having a blog is a smart move for a consultancy like Jupiter [Research]. The blog itself is an ad that says "Here we are, we are Jupiter, and this is how we think." Implicit but not explicit is "Maybe you'd like to buy our services?"

Notice any parallels with the holy grail that many corporate communications executives and agencies call Thought Leadership? It's about creating a leading position in the marketplace based on your thinking and expertise that will help you sell more of whatever it is you sell.

It's also why many companies would benefit from business blogging communities.