Abstract: Determining user intent based on current user query behavior comprising receiving from a client machine a plurality of signals indicating current user behavior when querying for items; tracking events of current user behavior indicated by the signals; and recommending items that the events indicate are items intended by the current user behavior. Seller performance may be and used in recommending the items. The recommended items may be ranked by a ranking algorithm that may comprise a boosted rank model algorithm that customizes ranking to each of a plurality of client machines.