Poker has a gambling element to it, which leads some players to question if poker is just down to luck. Although there is a serious amount of luck involved in poker, the fact the same big names regularly win in cash games and tournaments shows that there is skill involved.

The end of the boom is generally considered to be October 2006, when the Unlawful Internet Gambling Enforcement Act of 2006 (UIGEA) became law in the United States, and several online poker sites, including the industry leader at the time, Party Poker, left the United States.

Tetris. The best-selling video game of all time goes to the timeless classic known as Tetris. IGN says 520 million copies of Tetris have been sold, citing data from The Tetris Company.