YPN! Closed their ad serving program. You can promote affiliate programs.There is also AdBrite and Chitika but I have no experience with them.

Infolinks and Bidvertiser can be better alternatives

All of these, except Bidvertiser, are context links--not what I am looking for. Bidvertiser looks great. I may have a problem getting the code to work on some WordPress themes--they are set up for Adsense. Any solutions?
Thanks ever so much!

have you try kontera?
If it's a blog, why not use textlinkads (sell link)..
this is just advice