1. A system for updating relevance of each of a first plurality of items to a particular search query, the system comprising: a web server coupled to a computer network, the web server to receive the particular search query from the computer network, retrieve a search result comprising the first plurality of items, present a ranked list of the first plurality of items to a user in response to the particular search query, and receive a user selection of a particular item of the first plurality of items from the ranked list, wherein: each of the items of the first plurality of items is associated with a current weight for ordering the first plurality of items in the ranked list by relevance to the particular search query, and the first plurality of items includes one or more items displayed in the ranked list above the particular item selected by the user from the ranked list; a click log that receives information relating to the user selection of the particular item of the first plurality of items from the ranked list presented to the user in response to the particular search query; a ranking server coupled to the click log that, based on information received from the click log, dynamically updates the current weight associated with the particular item selected by the user from the ranked list, dynamically updates each current weight associated with each non-selected item of the first plurality of items displayed in the ranked list above the particular item selected by the user from the ranked list, and creates a meta-product tree by calculating feature weights for the search result, choosing a first feature with the highest weight, partitioning the search result into two groups, wherein a first group contains all items with the first feature and a second group contains all items without the first feature, selecting within the first group a second feature with the highest weight, partitioning the first group into two groups, wherein a third group contains all items with the second feature and a fourth group contains all items without the second feature, selecting within the second group a third feature with the highest weight, partitioning the second group into two groups, wherein a fifth group contains all items with the third feature and a sixth group contains all items without the third feature, wherein: the information received from the click log includes a position in the ranked list of each non-selected item of the first plurality of items with respect to the particular item selected by the user from the ranked list, each current weight associated with each non-selected item of the first plurality of items displayed in the ranked list below the particular item selected by the user from the ranked list stays the same, the current weight associated with the particular item selected by the user from the ranked list is adjusted according to a reward scaling factor, and each current weight associated with each non-selected item of the first plurality of items displayed in the ranked list above the particular item selected by the user from the ranked list is adjusted according to a punishment scaling factor; and a ranking database coupled to the ranking server that stores updated weights associated with the first plurality of items for updating the relevance of the particular item selected by the user from the ranked list and each non-selected item of the first plurality of items displayed in the ranked list above the particular item selected by the user from the ranked list to the particular search query.