A boost for making a deposit in a player's betting account places them in a better position to go on the treasure hunt. This bonus is good because it happens regularly in the course of gameplay. It is also easy to qualify for; nothing needs to be done besides making a deposit.
Slovakia is the only country with a capital city which borders two countries, Austria and Hungary. They have an astonishing 6000 caves, with one listed in the Guinness Book of Records. The Slovaks enjoy online gambling and sites are easily accessible here. They, however, do not have lots of sites, so they use foreign ones too.