The first type of bonus is a sign up bonus. The amount of this bonus starts from approximately 100 $, but it might go as high as 1000 $. So you should not join a casino, which offers a sign up bonus smaller than 100 $. Although it is called a sign up bonus, you will not receive it until you make your first deposit. Another type of sign up bonus is not a fixed amount of money, but a percentage of your first deposit. This type of sign up bonus might be good for you if you want to make a big deposit at first, so that the percentage will be more than a 100 $. If the money resulted by the percentage will be a smaller amount, you might want to consider joining another online casino. You will get a sign up bonus only once.
Another common type of bonus is the deposit bonus. This means that ever time you make a deposit, a small percentage, usually less than five percents is given to you as a bonus. I can not tell you the exact amount of money given to you as a bonus, since it depends only on the amount of money deposited. This type of bonus is very good, because you will get it every time you make a deposit. Try to look for a casino, which offers deposit bonuses.
Some casino bonuses require no deposit, hence the name no deposit bonus. These are generally quite small amounts of money, and they have high wagering requirements. The amount of the bonus is around 20 $, but it usually does not get higher than 50 $. Some of them are given only after you have wagered a certain amount of money, so eventually you will have to make a deposit in order to get the bonus.
The most common type of bonus by far is the sticky bonus. This type of bonus can be wagered but can not be withdrawn, that is why they call it a non cashable bonus. Of course, you can withdraw the money won by wagering the bonus, but you can not withdraw the bonus itself. There are two types of sticky bonuses; there is only a small difference between them. In the first case: the bonus will be removed from your account once you made a withdrawal. In the second case the bonus will not be removed from your account, it will remain there, until the amount of money is exhausted.
Many casinos offer a special type of bonus to their loyal players. This type of bonus is called Comp points or Loyalty points. The bonus works like this: the player is awarded one point after (usually) 10 $ wagered. When you have enough points, you can convert them in money, at a rate of 1 $ for 100 points. This rate is only an example; the actual rate should be listed on your casino's website.
Of course, not every bonus offered by the casino consists of money. You can get a bonus play, a free spin at roulette or at the video games and so on. The casino gives you a bonus even if you invite some of your friends. When they make their first deposit, and they refer to you, you will get a small amount of money. The sum varies between 20 and 50 $. So get started and invite your friends in order to get a referral bonus!
At the end, I want to tell you about a rare bonus: if you loose in a row for a longer period of time, the casino will give you back a small percentage of your losses. This bonus is very rare, and the percentage is somewhere under 10 %. This type of bonus is very rare, because only a few players are so unlucky to lose constantly for a month or so.
As you can see, a casino offers many types of bonuses, all in order to attract more players. When you choose an online casino, you should be aware of these bonuses, and make your choice taking into consideration the bonuses, besides other things. And let us not forget: the free plays are a kind of bonus, compared to land based casinos, where you have to play every time you play something. So we can consider free plays as a bonus offered by online casinos.
So go ahead, choose your casino, and take your bonuses. Good luck playing!