Which one is better adwords CPC @ CPA?

I start to thinking which one to apply in adwords CPC @ CPA?

as most of you notice we can use cpc @ cpa in adwords. But which one is most
effective to use. I've experience where cpc will get you the most traffic with easy money going out and cpa is quite good traffic.

anyone have a better suggestion?

 

If u think of selling or promoting programs I think email marketing is the best option than adwords.

 

thanks pdnocs,
that a good advice, let me try that instead of investing my money in adwords

 

I've tried to use adwords, but I just end up spending money and not making any in return. Any suggestions for finding the best PPC company?

 

i guess google, yahoo, and msn i start 3 of them in the same time

 

I just started PPC on Google Adwords and hope to see some positive result

 

I'm using PPC with adwords, I've only used specific keywords. It's been running for almost 6 hours so far, and I've gotten 4 clicks, which turned into one conversion. So far I'm happy.