Patent ID: 8370336

Claim:
A computer-implemented method comprising: processing a search query to identify item listings satisfying the search query, each item listing presenting an item that has been assigned to at least one category and on which a bid can be placed; deriving for each item listing satisfying the search query a demand metric based on the number of bids that have been placed on an item offered via an item listing, the demand metric derived using a half life formula such that a value for a bid contributing to the demand metric is reduced over time, as determined by the half life formula, wherein the half life formula has a configurable parameter representing the number of days until the value of an event contributing to the demand metric is reduced by half and the configurable parameter is configurable on a per item category basis; and presenting the item listings satisfying the search query in a search results page ordered at least in part based on the corresponding demand metric for each item listing.