In accordance with one implementation, a computer-implemented method is provided for inserting spot content into a media stream. The method includes receiving, at a client system, a media stream that includes one or more media content units and at least one spot marker. The at least one spot marker designates a spot location for inserting one or more spot content units and includes a category of a media content unit. The method further includes detecting the at least one spot marker in the received stream, and selecting at least one spot content unit based on the category of the media content unit. In response to the detection, the selected at least one spot content unit is inserted into the stream at the spot location, thereby generating a stream including the one or more media content units and the selected spot content unit.