how can i understand that a PTC site can become scam?

@hasandu (157)
April 15, 2010 7:43am CST
since new here, its tough to understand. recently i joind gagabux and neobux. i invested at gagabux and rented lot. now thinking how can i understand that it would not be scam? in general how u categorize whether a PTC trustworthy or not?
No responses