I myself have been involved in selling traffic for a few years... I get orders every week, with people wanting to make an adsense site and drive traffic to it.
This is the wrong answer. I have seen traffic convert well for people, but when all your trying to do is drive them to your site and praying to the web fairies that they click on your google ad,, chances are almost nill.
Like the above post said,, make a redirect page with catchy slogon , logo or image and grab their attention. Peak their curiosity level, convert the visitor sitting on the fence into a real visitor who will take the time to read over your site. If the information is not what they were looking for, hopefully you have made them curious enough that if they see a google banner on the side related to your site , they will click and go there.
Hope that helps, But buying traffic will work,, if your setup the right way to use it.