I think there are many similiar offers in the net now. Some is adult site that will give you referrals of $10 to $20 for new members join. Besides that most of the casino game site also have this kind of offers. I think signing up is easy, and normally they charge a monthly fees of your membership. First month is free but you need to cancel your membership before next month, this is a bit troublesome in most of the offers i found. Hope your offer is different.