Good advice Jon, I was just going to suggest we ask you to come and weigh in with advice. You are right on top of it.
It depends what types of things you are promoting and how you are promoting them. Targeted traffic is key, so the type of site you have could play a factor. For instance humor sites are tough to monetize. They can generate lots of traffic and curiously clicks but aren't necessarily good buyers. Same thing with forums and certain other types of sites. (Not saying all sites in these areas have a monetization problem - just using these very generally as an example.)