So I'm familiar enough with using Google ads, but what about when I want to choose who advertises on my site? What if I have multiple advertisers/sponsors and want to make sure they get equal time? What if a sponsor wants to pay to be the only advertiser of a certain section of my site? And of course there's the tracking and getting paid part.
What I'm really asking is, does anybody have any suggestions on free or cheap companies that provide services for this. I've tried to look at the source of some sites running ads, like Penny-Arcade, because I know they choose what ads run. But all I can tell is that PHP is involved, which is why I started this thread over in this section.
Does anybody have any suggestions?