Msg#: 4075017 posted 7:58 pm on Feb 5, 2010 (gmt 0)
Above on the right side, there is a link that says "About this data"
Estimated Statistics - Impressions, CTR, Clicks, Avg. CPC, Cost, Ad Position
If you enter a Max CPC and Daily Budget under Advanced Options, AdWords will estimate performance for your ad for the associated keywords. If you don't supply a Max CPC and Daily Budget for these estimates, AdWords will estimate your performance using a CPC that is predicted to always place your ad in positions 1-3 with an unlimited budget to capture all available impressions.