CPA= cost per action PPC= pay per click Copeac is a CPA company. PPC is a form of advertising (adwords, overture). I personally don't like Copeac but I heard that is a reputable company. (esti roman?)
And what is the best PPC? And please dont tell me about Adsense. I hate adsense, i had 3 accounts with them and all 3 have been closed within one months and different areas, different scripts.