To advertise using traffic exchange websites could be a solution in getting some PSA,it can be a solution for people who can't afford to invest so much;also if you use traffic exchange websites you need a lot of time,if you don't want to invest,in my opinion and from my experience,the probability to get some PSA from traffic sites is a small one,so if you want to invest time without money give it a try!You never know!Use the hit tracking if you go with more!