1. A method, executed on a processor, for serving a video content segment at an online resource, comprising: receiving, by the processor, a request for a video content segment; identifying, by the processor, one or more candidate video content segments in response to the request; accessing, by the processor, a quality factor (QF) and a bid for each of the candidate video content segments; ranking, by the processor, the candidate video content segments based at least on a combination of each of the video content segments' QF and bid; and providing, by the processor, in response to the request, a set of candidate video content segments based on the ranking, wherein the video content segments are video advertisements for promoted video programs, and the QF comprises content factors (CF), programs watched factors (PWF) and physical factors (PF), wherein computing QF=PWF*CF*PF, and wherein the physical factors (PF) include a length of the promoted video program, and wherein a short length of a promoted video program increases a rank of a video advertisement.