This thread is a bit old, but this information is very valuable, and I decided to give one more tip. Some of those bulk traffic won’t be seen, because your page can appear in an hidden iframe (1 pixel size).
So your logs really show visitors from many countries, but that doesn’t mean that they really saw your site.
I also bought some thousand visitors, from a “reputable” seller, but I got not even one free download. When I said to him that his traffic didn’t converted, he said that if it was so good, he would be rich.
So that is the true story. If someone has gold in his hand, why will he trade it for peanuts???:hithead: