If you are good doing SEO for your websites I think you have no problem with PPC. Here the most important thing to find keywords that will be effective. Next, you need to find sites where you buy traffic, preferably with good reviews. And another very important issue is the monetization of traffic. For example cpa networks, affiliate networks.
PPC can be very profitable if you know what you are doing. The best advise is to do a lot of research on how you can increase your ROI with PPC because that will help you the most.
PPC is a little expensive but the most important things are the results.If you site is good then you will get good results from here.