Before we sink into the beef of the different types of bonuses offered at online casinos, here are a few extra terms and points you should be aware of, so you can clarify them with a support representative before claiming a bonus, just so you know where you stand and what you're claiming.
1. Wagering requirements: Most bonuses have wagering or playthrough requirements, meaning that you need to play a certain amount before you can withdraw winning from your account. On average wagering requirements are usually between 15 to 40 times, however pay attention to what you are required to wager. In some cases it will be just the bonus times X and in others you will need to wager the bonus + your deposit amount X times. iBET The latter by the way is more common.
Another tidbit you should pay attention to with regards to wagering requirements is, that at most online casinos, if you request a withdrawal before you have completed the wagering requirements, all your winnings to date will be void. Not really fair, but this is reality.
2. Games played: Make sure you read the T&Cs in this case. Because slots games are generally the most profitable games for online casinos, many bonuses tend to be valid only for slots games. Usually scratch cards and keno will comply with this rule.
In other cases, you will be allowed to play your bonus on all games; however not all games will count 100% towards the playthrough requirements. For example play on slots will count 100% but roulette will only count 30%, meaning that you will actually need to wager over three times more in order to clear the wagering requirements and withdraw your winnings.