I’ve heard three people refer to the ‘RSS space’ at Web 2.0. This is dangerous hype. RSS is not a space, its a description of a way to transport links with clean titles.
Advertising in RSS feeds will probably be worth $100 – $150 million within the next 18 months, and RSS readers will eventually be baked into all browsers as a fancy bookmarking feature – and that’s it.
If people wanted to get excited about a piece of geekery that weblogs have helped drive then ping servers would be a better thing to look at. If you become the king of all ping servers then you have something that is a real threat to the core business of search engines.
When quantitative information such as price appears in RSS product feeds, then ping servers are hugely valuable and search engines based on crawling are fundamentally broken.