Abstract: Embodiments of the present invention are directed to systems and methods for facilitating real-time bidding in paid search. In some implementations, a real-time bidding agent receives advertisement context data that is related to presentation of an advertisement in response to a search query. Thereafter, a determination is made as to providing a real-time bid and a real-time advertisement for participation in an advertisement auction associated with the search query using the advertisement context data. A desired real-time bid and real-time advertisement can then be provided to an advertisement selection server for participation in the advertisement auction associated with the search query.