I agree with this. There is not one thing that can be done to improve your traffic.....there is fact a number of things that need to be done in order to get good traffic. On page optimisation, off page optimisation, content, then start to get your backlinks.
PR's usually give You good results. Traffic exchangers can give 100 a day in a snap. But the traffic is not really good. Try Traffic Swarm if You want...
Common man...Try to use video marketing. It is very best marketing. Use tubemogul. Free service. It can send 150 videos monthly.