Inserting advertisements into video content

Methods and systems to insert advertisements and/or other supplemental or replacement content into a stream of video content are described. In some example embodiments, the methods and systems receive a request to replace a portion of video content currently playing at a client device with supplemental video content, such as an advertisement. In response to the request, the methods and systems determine one or more fingerprints of the video content plating at the client device, identify one or more frames of the video content at which to insert the supplemental video content based on the one or more fingerprints, and insert the supplemental video content at the identified one or more frames of the video content.