The customer is king in an economic downturn … except at American Express.

AmEx has decided to prune its customers that fit under the bad-guy category with a unique offer.

Remember in the good old days when the Russians were still a player and your local bank gave you a blender when you opened a savings account. AmEx is turning this paradigm inside out, telling selected customers that if they’ll square away their balances and close their accounts they’ll qualify for a $300 prepaid gift card.

In short, AMEX is paying folks to stop being customers.

One gets the feeling that AmEx isn’t exactly proud of this brainstorm — no news release or other forms of proactive mass communications — and for good reason. It turns out that collecting the 300 bones in exchange for shutting down the account results is your credit score taking a hit.

While this hasn’t exactly triggered an uproar in the blogosphere I wonder if there’s some form of crowdsourcing at work.

If you click the entry point for the AMEX please-leave-us epiphany here you’ll see that the promotion has already expired.