Media is provided to a client device in response to a request with dynamically selected advertisements in near real time by performing a portion of ad selection operations as pre-processing before a media content request is received. One or more advertisements can be dynamically selected by an application server based on user data, advertisement parameters and other data to provide in the requested media. Attributes can be determined for one or more advertisement sets in which advertisements are placed within the requested media. The advertisement sets may be configured with the identified advertisements by an application server, and the requested media content and identified ads can be provided to the requesting client device.