If no wagering requirements were in place, what is to prevent you from cashing out your bonuses and their related winnings immediately after you redeem them? This would render it possible for you to skip from one casino to the next, cashing in on the operators’ generosity.
So, wagering requirements enable gambling operators to financially protect themselves against bonus abuse, which was a prevalent practice after the first online casinos hit the internet. Back then, many smart players understood that these offers presented them with an opportunity to turn a nice profit without risking anything. They would register at a casino with multiple accounts, opt in for the welcome bonuses, and cash them out as soon as they could.
They soon realized they needed to tackle the loopholes that allowed players to exploit promotional offers while still being able to incentivize new customers with appetizing bonuses.
Naturally, these precautions work to the detriment of such players as they make it all the more difficult to release the cash from their accounts
So they came up with the idea to attach wagering to their offers to act as a safety cushion against bankruptcy and bonus hunting. Additionally, players were prohibited from opening multiple accounts at one and the same casino, with each new customer being permitted to opt in for the same welcome offer a single time only.
There are several reasons why bonus wagering is detrimental to players, starting with the time restrictions imposed on the bonuses. Customers usually are given a specific timeframe in which they need to clear their wagering. If they fail, their bonuses will expire and the free funds will be automatically forfeited from their balance. The timeframe for bonus validity usually ranges from one week to a month.
Wagering often restricts you in terms of the games you are permitted to play. There is one such thing as game weighting where different types of games have a different contribution toward your bonus wagering. Slots and keno, for example, usually have the highest contribution of 100%. This means each time you bet say $100, the same amount will be cleared from your bonus wagering.
In contrast, other games like video poker, blackjack, and roulette often have a much smaller contribution, sometimes as low as 20% or even 10%, so if you wager $100 on these, only $20 or $10 will be cleared from your wagering requirements. In other words, you will have to risk tons of money when playing these low-weighting games before you manage to cover the wagering of your bonuses.
Some gambling operators go as far as altogether prohibiting players to bet on table games and 
video poker with an active bonus in their balance. Violators have their bonuses removed from their accounts along with any resulting winnings.
On top of it all, some casinos have rather high wagering requirements (up to 100x!) that are next to impossible to meet within the stipulated timeframe. The purpose is to reduce players’ chances of actually cashing out their bonuses. Imagine a gambling newbie redeeming a bonus of $100 with 50x wagering that remains valid for a 7-day period after redemption. A casual player can hardly afford to pour $5,000 into an online casino within a week. Chances are they will lose both their bonus and the triggering deposit before they succeed in clearing the playthrough.
The results of such practices were disastrous for online casinos from a financial perspective
Last but not least, some online casinos are in the habit of enforcing higher bonus wagering for players from specific countries due to the high levels of bonus hunting from these jurisdictions in the past. This is the case with players based in Denmark, Poland, and Israel who are forced to adhere to bling websites.
