After more than a year in development, Yahoo Inc. today revealed details of its new search ad system and technology details, API, to third-party programmers in the advertising world who wants to build additional software tools.

The system will include new tools for scheduling campaigns and tracking performance. A free Yahoo software will be available for advertisers to be able to track user activity on their site and more effectively judge the value of their ad campaigns with Yahoo as well as its competitors.

Yahoo's new tec

hnology for setting ad positions will use a quality score that incorporates a "big basket of measures," including bid price and the rate at which consumers click on ads, said Tim Cadogan, Yahoo's vice president of search and sponsored search. To date, Yahoo has ranked ads based on bid price alone, which hasn't allowed it to make as much money as Google.

Advertisers will also be able to target potential customers by geographic location as well as user-behavior.

The release date is expected to be announced at Yahoo's annual meeting with Wall Street analysts on May 17