While casinos offer many kinds of bonuses to get players to make an initial deposit with them, they also offer all kinds of bonuses aimed at getting long-time players to make additional deposits into their accounts. One way they do this is by offering monthly or weekly recurring bonuses, where each time period you can make a deposit and receive a certain percentage of that deposit as a bonus to your bankroll.
Usually you can only take advantage of these bonuses once per cycle, and they typically have similar wagering requirements to those of match bonuses. Since not all online casinos offer these kinds of bonuses, you might want to consider that when you are making an initial decision about whether to sign up for a certain casino or not.
For those players willing to deposit a very large amount of money on their first deposit, casinos are willing to offer additional bonuses. While a high-roller bonus will typically be for less than the 100% match bonus offered for standard deposits, they also have higher maximum amounts. So you might only be offered 40% as a bonus, but the maximum amount of the bonus might be $2,000 instead of $200. These bonuses are only offered by some casinos, and can vary widely from casino to casino. It is best to contact the casino directly if you are interested in making a large deposit so that you can get the complete information and terms and conditions regarding these kinds of bonuses.