>I think you do not understand Yahoo Search. 99% of the index is made up of freely crawled pages.
Actually the real question for many webmasters is that under Yahoo's current system of presenting serps results what percentage of clicks goes to freely crawled pages.
Outlay of results is very clever, with sponsored results taking up almost all of any surfer's attention space. For example, first page of any commercial search will, in general show, mostly sponsored results, with at most 2 and most likely 1 or partial results from the algo search shown towards the bottom. Towards the bottom of the 20 results page, we have another set of sponsored results.
Go to second page, and the process is repeated.
Add to this some placement avdvantage gained by sitematch pages.
Research indicate that most surfers are likely to click whatever is shown to them first.
My guess is that for commercial searches of any importance, freely crawled pages get only 1% of the clicks. Essentially, freely crawled pages are used as carrots to lure the surfers and then divert them to the sponsored listings, in my view.