Even though many games heavily involve instant-gratification sort of feedback, they still take a decent amount of effort to turn on, load the file, progress in a game, retry stuff when you fail, etc., etc. Unless you're talking about browser or phone games, most games really aren't a pick up and play sort of thing.

The internet, on the other hand, is like a weapon of mass destruction aimed squarely at society's attention span. If you think it might help, there are various browser plugins and programs designed to break you of the constantly-checking-your-favorite-websites habbit. For instance: a of the psychology behind it is the ability to instantly reach the website in question and read what you want to read. Download one of the plugins that puts a 30 second delay before loading selected websites and you'll find that habbit gone pretty quickly.