ESTIMATING INVENTORY, USER BEHAVIOR, AND/OR COST AND PRESENTATION ATTRIBUTES FOR AN ADVERTISEMENT FOR USE WITH AN ADVERTISING SYSTEM

An advertiser may be provided with fast and accurate estimates of the future performance of at least one of their advertisements. These estimates may be broken down by keyword, thereby providing, up-front, useful information to the advertiser about how different keywords will affect the performance and cost of their ad campaign. Estimates and/or suggestions for a set of keywords, given additional campaign parameters, may be generated by using historical search traffic (or some other ad serving trigger) data to predict future inventory and to find useful keyword (or some other serving constraint) variations. Current data on competing ads may be used to simulate the competitions (e.g., real-time auctions) that the given ads will participate in.