The sale of boxed games has been in decline since 2008. That decline accelerated last year. Soon there will be no boxed games. Using plastic and cardboard to distribute digital data is plain silly and is only hanging on at the current level because of the heritage console platforms.
There is a movement towards online free to play titles such as World of Tanks and CSR Racing. These allow the player to enjoy the game without paying and to only invest in it if they want to. This superior business model is hastening the decline of boxed games.
Then there are mobile phones and tablets. These benefit from portability and app stores with hundreds of thousands of titles. They have become the main gaming platform with Angry Birds, for instance, having been downloaded over a billion times.