Actually people think and hope their bets will win and make huge money, but in fact gambling is losing money in the long term, because house has edges, bookie has margins, and deposit bonus kills, eventually we are always losing money.
If this can be done correctly chance to win is also there but if played unresponsible for sure a big loses will follow people tend to think that gambling is just a sort ot enjoyment as long as you still afford the amount that you are losing you keep playing and try to win.