American Express-Costco Divorce Shakes Up Credit-Card Industry

This is interesting, at WSJ, "Costco Cards Account for One Out of Every 10 AmEx Cards in Circulation":

American Express Co. and Costco Wholesale Corp. are ending their 16-year relationship, a surprise move that pummeled AmEx’s stock price and will trigger a major upheaval in the card industry.

The unusual partnership, in which Costco exclusively accepted AmEx cards, had driven a significant chunk of business to the New York card company. In addition, AmEx and Costco issued a credit card together that could also be used at other merchants. When the arrangement ends next year, millions of customers will be forced to use a different credit card when shopping at the wholesale store.

The failure to agree on new terms was a fresh blow to AmEx, which was already falling short of some sales targets. American Express Chief Executive Ken Chenault said the move, affecting roughly one in 10 AmEx cards in circulation, would eat into the company’s results in the next two years.

On Thursday, AmEx’s shares dropped $5.53, or 6.4%, to $80.48, its largest one-day percentage decline since August 2011.

The move sets up a race among credit-card firms to team up with the fast-expanding wholesale club, which sells everything from car tires to smoked salmon...

More.