A method and system for generating notifications of auctions based on user
notification requests. In one embodiment, the notification system
receives from users selection specifications that specify the types of
auctions for which the user is to be notified. The selection
specifications may include a category of the auctions, keywords for
identifying auctions, and values for attributes associated with the
category. When the notification system receives a selection
specification, it determines whether that selection specification is the
same as or nearly the same as other selection specifications that have
been received. The notification system periodically determines whether
any new auctions satisfy a selection specification by submitting a query
to an auction database and then notifies the users when new auctions are
identified. The notification may include a list of auctions that is
sorted based on access patterns of users who are presented with lists of
auctions using selection specifications with similar category, attribute,
or keyword values.