What is the different between PPC and PTC?

[henriyo]

What is the different between PPC –paid per click and PTC –paid to click? I know some websites like neobux, palmbux or gagabux are PTC sites where we are paid to click ads everyday. And PPC is something like adwords or adsense.

[Ieronimud]

Both the terms are being used synonymously these days but they certainly difer from each other.

PPC sites are those such as Adsense, Adbrite etc which pays its publishers when someone clicks on the ad displayed on their website.

PTC refers to sites of kind bux.to which most of them are spam. There are tons of such sites but most of them are scam. Few legal ones that I know are bux.to and clixsense.com