I have a niche high market value site, generating a CPM of about $26, with a very healthy CTR. It's only a little side project and doesn't receive that much traffic, so it's certainly not my main business. But just goes to show, you don't necessarily need millions of page views, or indeed hundreds of thousands if you select your market wisely.
If it's getting $26 ecpms, why aren't you buying assloads of adsense traffic for it? If you have good retention, surely you can buy customers for less than you make off of them. If each customer averages only $100 pageviews that's still $2.60 a pop.
It's a project from a few years back that failed to live up to my misguided immediate expectations. So it was put on the back burner and now and again I look back and its been making steady progress. I'll get back to it soon and see if I can crank it up a few gears. The investment in time has been done, and it has a foothold, so now it should just be a case of expanding on what's there.
I'm not sure if what you have described would work for my particular site, I think id need an actual product rather than just articles and content, otherwise it's a bit of a gray area?
Google will HEAVILY penalize you if they think you are doing "arbitrage" (paying for ads to get visitors who you hope will click on ads) because they think this makes for a sucky user experience. It is fairly easy for them to figure out who is doing this, considering they own the best CPC program in the world to get traffic (AdWords) and also own the best CPC program in the word to sell your traffic (AdSense). That gives them plenty of data to be a law unto themselves, but they have other sources if you decide to be tricky and try something like Yahoo CPC -> you -> AdSense.
Source ? AFAIK, google will penalize you only if the target site is filled with ads. If the target page has useful relevant content then google doesn't care. This is an accepted practice and high profile people have indulged in it (shoemoney for example) without getting penalized.