Over on ihobo today, the reason why it simply doesn’t matter how many players finish games:
Players by and large do not finish games, because a player’s enjoyment of a game has nothing to do with whether or not they finish the game. It is perfectly possible for a player to leave a game unfinished and still feel they have had excellent value for money from it – especially with a playground world like GTA. In our player studies, we found many people who would mess around in Vice City or San Andreas when they got home from work who simply didn’t care about whether they would ever finish the game. The game was entertaining them immensely – finishing it was not a factor.