One thing to help tell if a site is a scam is to do a whois lookup on the domain and see when it was first registered. If it was created that week, it is more likely to be a scam. Usually these scams are created quickly and dropped. If it has been around for awhile it is more likely to be safe. But do note that a scammer could have sat on the domain for a while before using it. The registration date in whois is not something a scammer can fake.