PTC and Paid to surf sites are the one where you are paid to view other websites. You are paid with 0.01$ (most of time) for a 30 seconds view. There are also PTC sites where the rate is a s low as 0.001$.
A few website owners advertise on these sites for tarffic at low cost. The traffic however does not convert into anything useful because people just click ads on some 6 or 7 PTC sites at once.
Google does not allow sites that advertise on PTC sites into their Adsense program. Check your traffic sources if there are any such or similar sites.
Apart from PTC sites you should not be a part of any traffic exchange, banner exchange or other similar programs.
Try adding pages like Terms of service, Privacu policy and other similar things. I raed somewhere that these pages are required.
Google also states that a top level domain is required but I'm not very sure about it. The best thing would be to have a custom domain if you want to get accepted into adsense.