I can't speak for the business that you mention, but I have tried that sort of service, and they have all been frauds. They just run programs that load up your page every few minutes.
I logged the 'visitors' with a php script I developed and found that only two IP addresses had visited my site when the stats panel for the visitor provider said that they delivered 5000 unique visitors. My javascript stats program logged aboslutely nothing because 5000/5000 visitors seemed to have javascript disabled.
Now I tried this with more than 5 providers with similar results. Although I never used targetedvisitors.biz, I can only asume that they use a 'wholesaler' that uses the same methods.