15. The system of claim 14 , wherein statistical information relating to the performance of a particular keyword is extrapolated for a first application based on the known statistical information of one or more other applications and a similarity measure between the first application and the respective application of the one or more other applications.
14. The system of claim 13 , wherein the determined plurality of keywords include keywords identified as having statistical information relating to the performance of the keyword for a particular application of the plurality of similar applications based at least on a measure of revenue per thousand impressions.