A system including a digital component request server that receives digital component requests for a supplemental digital component that will be presented in an additional multicast stream that is different to a multicast stream that is delivering content; a digital component distribution server that i) selects supplemental digital components to distribute over the additional multicast streams, the supplemental digital components being selected for one of the additional multicast streams being different to the supplemental digital component selected for each of the other additional multicast streams, and that ii) assigns one group of a plurality of groups of the multiple client devices to a respective one of the additional multicast streams; and an instruction generation server that generates instructions for the multiple client devices to tune to the respective additional multicast streams assigned to the group of multiple client devices that includes the different client device that submitted the request.