With a cash back, you actually get a refund of the money you deposit in your betting account. Sometimes it is the deposit cost that gets reversed or a certain percentage of the deposit you make. The benefit of such a bonus is that you receive your reward immediately; it is available without conditions.
El Salvador is among the smallest Central American states. Once a part of the mighty Mayan empire, it still houses plenty of archaeological treasures for scientists and tourists to appreciate. While gambling is a difficult subject in El Salvador and brick-and-mortar casinos are all but banned, there seems to be no regulation on mobile casinos.