Why do video games (flash, console, and PC) rarely ever reward you for 100 % completion? If users got to play a special level, earn new character, got to view a cool cut-scene/ video, or something like that, but usually nothing happens, you just see that it's 100 percent completed or you get a reward that wasn't worth the effort.
So, what are your thoughts? Are there any games that have given some extreme rewards for 100% completion? Why don't video game makers reward their dedicated players with something more special?