I don't understand this offering 5BTC bonus, is that for real or what? and one person above already complaining about this site, I don't think it is actually true, whether it is up front or by monthly payment.
Maybe it is an offer to attract people and later on decline their withdraws I think.
This bonus is not instantly added to your account, they have a formula to calculate the bonus value, after you bet money, the bonus will gradually release.