iGaming behavior

"777" and Fruits still work? Not only that they work, but still dominate the majority of iGaming operators lobbies. Why is that? The first slot machine originated from poker back in the days and was a glorious sensation at that time. Game of poker, which requires some calculating skills and determination, essentially raised in a totally different angle. It's still a funny combination of pictures, but its simplification and logic settled a start for something, that appeared to become a multi-billion industry for upcoming ages.