Various merchants entered into an agreement with American Express that required all disputes to be resolved by arbitration. The agreement also specifically provided that no claims could be arbitrated on a class-action basis. Despite the class-action waiver, the merchants instituted a class-action lawsuit against American Express, alleging violations of certain federal antitrust laws (the Sherman Act and the Clayton Act). They claimed that American Express had used its "monopoly power in the market for charge cards [cards requiring payment in full at the end of each billing cycle] to force merchants to accept credit cards [cards requiring payment of only a portion of the balance each billing cycle, with interest charges added] at rates approximately 30% higher than the fees for competing credit cards." (This is termed a tying arrangement.) American Express responded by moving to compel individual arbitration under the provisions of the Federal Arbitration Act (FAA). The merchants sought to invalidate the ban on class arbitration by introducing evidence that (1) the cost of proving the antitrust claims via expert testimony would range from "at least" several hundred thousand dollars to more than one million dollars while (2) the maximum recovery for an individual plaintiff would be only about $12,500 (or about $38,500 if the plaintiffs were awarded treble damages, which they sought). Who won? Explain. American Express v. Colons Italian Restaurant 133 S. Ct. 2304 (2013).