While the great majority of traffic brokers will send useless traffic (whether it be bots, popups or just geo targeted low income countries) there are plenty that will send quality, reliable traffic. I can turn a consistent profit form a few sources - you just have to match quality traffic with targeted landing pages. Do your research and don't discount traffic brokers out of hand.
organic traffic is best than any others. You can get real visitors but you will pay them to view your site. they are called PTC.
I agree with what the others are saying. I purchased traffic once. Some incredibly cheap deal like 100,000 visitors for $29.95 or some BS like that. Being very green back then I figured even if the traffic is not that great and I only convert a tiny fraction of a percent I'll make money. The problem is ZERO is smaller than a tiny fraction and that's what you'll get from purchasing traffic.