If you do PPC to EPN, you need to clone your site and do split testing. Let me explain. Let's say you have foo.com. You have one site at the root of the foo.com. Then create a folder called site001. Copy the content of root to the folder site001. Then clone the sql database in phpadmin (let me know if you need more instructions on that).
Okay, now in EPN create two campaigns, foo and foo1, with the latter attached to the cloned web site in folder site001.
When doing PPC, having half your adgroups pointing to foo and the other half pointing to foo1. Do at LEAST one of month split testing, at the end of the month you will be see whether foo or foo1 is more profitable.
If you are really an eager beaver, you can make foo2 cloned site and use that to test keywords that you suspect are really shiite. Since I started doing this method, I've eliminated several groups of keywords that generated bids but never really converted.
Oh, and one last thing. EPN is really seasonal. Like in December, it's really hard to NOT make money. And the first week of January, well for most niches just turn off the PPC.
