A wagering game system and its operations are described herein. In some embodiments, the operations can include monitoring gaming-related events at a wagering game machine of the wagering game system to detect a promotion trigger event. The operations can also include determining information associated with the promotion trigger event, and providing the information associated with the promotion trigger event to a promotional content server of the wagering game system to cause the promotional content server to select promotional content based, at least in part, on the information associated with the promotion trigger event. The operations can further include receiving the promotional content from promotional content server in response to said providing the information associated with the promotion trigger event to the promotional content server, and presenting the promotional content at the wagering game machine.