Both companies are trying to help small businesses by promoting Small Business Saturday on November 26, 2011 (the day after Black Friday).
From the Amex Small Business Saturday Facebook page
American Express wants to help you make a difference. Get a one-time $25 statement credit when you register an eligible American Express Card and use that Card for a purchase of $25 or more at a small business on November 26th. Registration is limited. Terms and Conditions apply.
From the Fedex Facebook page
Come back on Nov. 1st at 1pm ET, to get your $25 American Express Shop Small Gift Card and use it to help support local businesses on Small Business Saturday, Nov. 26th.
This Fedex promo is open to anyone, but they are only giving away 30,000 of these gift cards. More details are provided in this Fedex press release