14. The invention of claim 13 further comprising: receiving search result sets from at least some of the matching suppliers including data related to click through rates for ads related to at least some of the results in the search result set provided by each of those matching suppliers.
13. The invention of claim 2 further comprising: repricing at least some of the ads from bids provided by the matching suppliers in accordance with data related to estimated click through rate for each ad before delivering the search result set in response to the query.