I almost always use a single sponsor per free site. One should never use competing sponsors together because that's saying 'this is the best damn tit site, but if you don't think so, this one over here is better'. So if you are going to market a secondary sponsor, it should be a product. But it sounds like that is what you are doing. For me, it is all about simplicity of advertising and moving the surfer towards what I intend on selling on that particular site. If I want to sell midgets gone bad, then I only promote nasty midgets. I won't throw in an ad for rectal lube hoping the surfer loves angry little people and has an especially dry poop shoot.
