Just 3 days ago i`ve got sign up bonus(with promo code) for $50. The only way i could use it - to bet $20 and $30. Yesterday i won $40 for one of the bets and i withdraw it without any problems. So it is possible to get some profit from such bonuses, but it is difficult enough. I see such bonus with so easy rules to withdraw the first time and don`t sure that can get such bonus again.
You are talking about which gambling site? It seems pretty easier terms and conditions, you got 50$ sign up bonus then you rolled it only for two times? I have some experienced in a few gambling sites, i got sign bonus but i have never been able to use it properly because it was quite difficult to win for me.