Here is my honest review I did a test 10k visitors package. My niche was entertainment and viral news. I would get 600-1000 impressions per day, I would get 1-4 clicks during the week. On the weekend is when my clicks peaked from 6-12 clicks per day. I have not reached the threshold yet but using their traffic I have gotten halfway there literally, but I am confident I will soon. (this traffic seems to be adsense safe)
Michal's customer service has been excellent he usually answers in 24-48 hours and answers all questions. There were two days when I noticed my traffic dropped very low to 40-50 visits, I shot an email and he took care of it right away and my visitors increased.
With some high paying keywords (which I don't currently have, but plan on putting up a few high paying keyword sites soon) this could be very profitable. For me all I cared about was the consistency of the visitors, Webgeek's communication, and if some of these impressions produced clicks. Now all I have to do is wait until I reach the threshold and expect my first check.
The only real cons I see are the low clicks, but it also good because you don't want to look suspicious. The only con is you can't track the visits by G analytics.
Regardless of the two cons, I will be a repeat customer for life.