Bitmob - On the Contrary: Unlockable content sucks.
Sports games are a classic example of a design that creates a fair playing field from day one. With most of these games, the skill of the player is what determines the outcome of the match not the unlockable content. Sports games also have a high replay value - until the next season – and the replay lies in the drive to perfect the control mechanics and not the quest to unlock all that is hidden in the game.