High-roller bonuses are offers that casinos give to their customers when they deposit big sums of money. Such customers are called high rollers and the larger the amounts of money they deposit, the more they get rewarded. Casino providers anticipate that players with money on their accounts will play and if they lose, they'll deposit more money.
South Korea is known for some of the best English teaching establishments in the world. People from many English-speaking countries travel to South Korea to teach English. South Korea can become a very busy and claustrophobic country. This is why people prefer to gamble online as opposed to going into a casino.