I am a staunch believer in "G"'s penalties for people buying traffic. What most don't realize is this traffic is garbage and although a timer may run. You still only get non-targeted traffic.
Never bought any traffic, well not all are against google's tos. There are some that do targetted traffic and it sends real people to your sites but still havent used them.
The key ingredient that I have seen in all of these "paid" traffic sites is the need to give up yur personal info. I just think alot about the spam thingy and how much a fresh account of gmail that I have has been exploding with spam since registering for some of these services as an experiment.
These traffics are not targeted and will not bring any sales or clicks on your websites.
Instead try to purchase links for your sites and then rely on search engines to send you traffic.
I bought traffic before it was the biggest waste of money ever.. i only got 1/5 of the traffic i was supposed to and it was all untargetted traffic that got added to my cpanel's 0-30 second visitors... Never again. Either do work yourself and get good traffic from SE's or get like adwords or that type where its targetted traffic and it could actually lead to a sale.