There is no one unified deposit size. Some players hit the jackpot while playing with $100, while others spend $1.000 and can’t win even half of the jackpot. The thing is that you should always use only 10% of your bankroll to stay in the black even in the case of losses. Thus, the more you deposit, the more bets you’ll make, and the more chances to hit the jackpot you’ll have. But in any case, it is a matter of luck.