High roller bonuses are casino rewards which are offered to punters who often spend more than average amounts of money in the casino. They are in many ways preferential, and casinos make no effort to hide that. It is essentially a 'scratch my back; I scratch yours' arrangement.
Basically, high roller bonuses are VIP bonuses. They are similar to other bonuses in concept, but there is a significant difference in value. Where ordinary players may be receiving $5 in bonuses, high rollers could be collecting upwards of $500. Where regular players get 50 free spins, high rollers receive them in their hundreds.
Despite their vast size, high roller bonuses are also subject to casino terms as tight as those stated for other bonuses, if not tighter. Casinos know that high rollers are likely to make outrageous bets which could bring the house to its knees if they were won.
As such, online casinos try to protect themselves from these daring gamblers by placing conditions on high roller bonuses. These could be in the form of restriction of the number of games such bonuses may be used in and setting protective wagering requirements which players are unlikely to chase easily.
High rollers bet big even with their own money and place seemingly outrageous bets. There is, therefore, no imagining what they could do with free money; many of them use these free bets as a chance to make a once in a lifetime bet, a sort of all-or-nothing wager.
They may also use these bonuses to play games which fall outside their usual realm of fixtures. Usually, these are high-risk, high returns bets that the casino hopes against hope do not go the punter's way. Luckily, the outrageous bets almost always end up in player losses, and casinos get to keep their money.
Sometimes, however, high rollers decide to use the money they get in the form of bonuses to play for real money. Usually, these are people who have gotten burnt placing considerable bets in the casino and are making a desperate attempt to recoup their lost money.
Such players can be dangerous to the casino, and the houses know this all too well. While they are risk bettors, they are also calculating individuals, and scary even when their winning chances are low. They go for games such as slots where they are likely to land substantial jackpot wins.
The wagering requirement remains the saving grace for the casino when high rollers play with their bonuses. Houses know that even if high rollers win, they are likely to abandon the win, because of the wagering requirement. Even if they were to pursue it, the casino gains from the money used.
A high roller who uses a $10000 bonus to win a million dollars is likely to be playing with a 20x or more wagering requirement. They would thus be required to spend $200000 to trigger their winnings. This will take a while, by which time the casino is likely to have made money from other bets.