What is involved with getting an American Express Black card?

The American Express Black Card is the commonly used name for the American Express Centurion Card which happens to be colored black. To obtain the Black card one should have an unblemished credit history, spend at least $250,000 annually on a Gold or Platinum card, pay a joining fee of $5000 and an annual fee of $2500. One also has to have a certain level of "net worth" which Amex has not disclosed.