Buying traffic from Traffic brokers is a trail and error thing. There is no magic traffic you can buy that will instant bring you the big sales. However if you tweak your pages and try how bought traffic responds on your pages it is possible to make some money. Its best to find traffic that responds with the sort of content you are trying to push. And in my humble opinion it pays to search for a niche that is not promoted by everyone on the net. There are so many webmasters trying to sell memberships for the same sites over and over again, even surfers are getting enough of it, try to find something new and fresh and find traffic that is looking for the same material you are promoting.