25. Apparatus comprising: a) at least one processor; b) an input for accepting ad scores wherein each of the ad scores indicates a value of a user selection of an ad; and c) at least one storage device storing a computer executable code which, when executed by the at least one processor, performs a method of 1)scoring a document using ad scores of the ads when the ads are served with the document and ad scores of the ads when the ads are served across a collection of documents to generate a document score, 2) accepting a cost for an action with respect to an ad when the ad is served with the document, and 3) adjusting the cost using the document score to generate a modified cost.
25. Apparatus comprising: a) at least one processor; b) an input for accepting ad scores wherein each of the ad scores indicates a value of a user selection of an ad; and c) at least one storage device storing a computer executable code which, when executed by the at least one processor, performs a method of 1)scoring a document using ad scores of the ads when the ads are served with the document and ad scores of the ads when the ads are served across a collection of documents to generate a document score, 2) accepting a cost for an action with respect to an ad when the ad is served with the document, and 3) adjusting the cost using the document score to generate a modified cost. 32. The apparatus of claim 25 wherein the document score is less than one, and wherein the act of adjusting the cost includes multiplying the cost by the document score.