A system is disclosed for expanding a user query based on user learned
popularity rankings. User queries often have no exact match, resulting in
a user having to refine or abandon the search. The disclosed system
obtains popularity rankings based on the content of a user query. The
system expands the user query based on the popularity rankings.
Thereafter, query results based on the expanded user query may be
provided to the user. The system also regularly learns from user behavior
and adapts the popularity rankings according to the learned information.