Does anyone know if CJ allows you to advertise their offers with PPC advertising; like adsense or facebook?
I've tried CJ once, and being a PPC user I couldn't bid on the product names, so I stuck to clickbank.
CJ doesn't have a policy against PPC. But PPC restrictions are up to each individual program. Some programs are wide open, some restrict brand name bidding, some restrict certain keywords. All kinds of variety. So you just need to read the TOS for the programs you are interested in promoting.
As Linda said, terms vary by merchant. Check the program description, Keyword Link, and Special TOS (if a program has any) to see if it's allowed or not.