I use ppc advertising and I can tell you the result was terrible. I used web traffic agent and Cpv marketplace, I get decent amount of traffic from them, but I did not get what I was expecting which is making sales. The traffic that you get from those sites may not be targeted enough which may make it quite hard to achieve sale. I've not tried clicksor and I can't really tell you how it works.
I really believe the possibility for you to be successful by advertising on those ppc network will depend on your chosen niche. Often time people who are on the those networks may not be interested in what you are trying to offer.