I was recently banned from CJ for doing something similar to this, including spoofing the referrer (using a similar thing as brad's CPA-r). It's very very easy to catch. here are some of the ways they know.
1. User agent - Many PPV companies append a custom user agent to all your traffic, this is a dead giveaway. and no matter what you do, you CANNOT blank/spoof this. It's created at the browser level, and no client side scripts have access to change it.
2. MediaTraffic (for example) forces their popups in I.E., regardless of what browser the user is actually using (this is retarded, if you ask me). So all your traffic will come from I.E. browsers. another giveaway
3. CJ and it's advertisers actively monitor for people bidding on their domain names with PPV. They have systems with Mediatraffic, Trafficvance, Zango, etc, software installed on them. If they load up their URL, and your affiliate link pops up. you're gone.
4. (this is how they caught me). When you use PPV, the user must load your "target" URL before the adware software can register that it needs to show your popup. Once it figures this out, and pops up your popup page, the URL is loaded again (this happens within a very short amount of time). So CJ can see this:
T = Time
@ T = 1 : user with IP XXXX loads the target URL (in this case, probably a CJ advertiser URL)
@ T = 2 : user with IP XXXX again loads the same URL, this time with an affilaite link attached.
the time between T1 and T2 is very short (< 1 second, most of the time).
This leaves a VERY noticeable footprint in their traffic logs. This was the one thing I didn't have covered, and they canned me for it.
Bottom line is, you can certainly try this, and you will probably get away with it for a while (I was doing it for well over 6 months before i got caught), but you will eventually get banned.