Welcome bonuses are frequently 'deposit match' rewards. This means that when you open a casino account, the bonus will match your deposit (up to the max amount in the offer). A bonus might offer you a 100% match on your first deposit, between €20 and €500 – meaning a deposit of €20 would top-up you account with another €20 in bonus cash, while a max €500 deposit would give you an extra €500 bonus. You can find some offers that offer rewards on deposit your second and third deposit.