When I first started with Adsense I was making some nice money. These days, I'm making significantly less money than I was before even though I'm making much more money than I was before. So I want to test out some other programs. But I've been using Adsense exclusively for so long, I don't even know what else is up there. I did sign up for Yahoo Publishers network a few months ago but I haven't heard back from them. Are there any other good programs? I'm looking for some traditional sized banner ads. What I'm thinking of doing is joining a few programs and rotating the ads via php. Is that a no-no?