Where in other sports, a player's contract determines his or her worth, soccer is different: players are ranked based on their transfer fees. A transfer fee is a sum paid by the club wanting to acquire a player to the player's old club. In effect, it determines the market value of a player.

European football clubs are especially known for the transfer fees given to players they want. The lion's share of the Top Ten belongs to two Spanish La Liga clubs, namely, FC Barcelona and Real Madrid, proving that not only do they have deep pockets, but are more than willing to get the best players money can buy.