H.3.3 [Information Storage & Retrieval]: Informational Search and Retrieval – information filtering, retrieval models. General Terms

How much is a keyword worth? At the crux of every search is a query that is composed of search keywords. Sponsors bid for placement on such keywords using a variety of factors, the key being the relative demand for the keyword, and its ability to drive customers to their site. In this paper, we explore the notion of "worth of a keyword". We determine the keyword's worth by tying it to the end criteria that needs to be maximized. As an illustrative example, keyword searches that drive e-commerce transactions are modeled and methods for estimating the Return On Investment/value of a keyword from the association data is discussed