No, it doesn't matter if they're processing 100% American Express card transactions that may be at a higher rate, we don't charge the merchant any different pricing. Whatever the funding mix is—that being a variable cost that's going to vary from merchant to merchant, from time period to time period, and by how many of their transactions are basic cards, premium cards, Visa, MasterCard, Amex, bank transfers, or cash balances—we don't charge any different rate to the merchant for that. It's a flat net rate that's published on our website, and that hasn't changed in over eight years.
On November 21st, 2011. See this statement in context.