Will it catch on?

I've just had an idea for a new casino venture. Lets say a punter deposits £100 I will offer him a £50 bonus. Now I know I will have an edge in my new casino but to be honest I'm not going to be happy with just that.
I need more. So my idea is that when the punter bets, If he loses I will take it from the £100 but If he wins I will add it to the £50 bonus and make him wager £7500 before he can get any money he might have won risking his own money. I'm not sure they will fall for this and maybe a £50 bonus is to much, but there again the punter will have to bet £150 to win a £1. What do you reckon? Will it catch on.