Check out your referral logs.. notice a pattern? If your logs are like mine, a HUGE percentage of your hits are coming through a search engine (Google, Yahoo, MSN)... Here is 3 minutes worth of referral logs from my blog...
In a world where a good percentage of your content is dynamically created and displayed in Ajax or Silverlight, how can you enable search engines to find your data?
Well, a bunch of folks across the web have been doing some thinking on this. Jonathan Hawkins recently did a session at mix on the topic and posted some thoughts. Nikhil also discussed the issue in his talk at mix and posted some interesting techniques as well.