American Express has really made a huge push for small business with a variety of statement credits for using your American Express card at small businesses. The latest one I knew about, and took advantage of, involved Foursquare  and syncing an AMEX card. This time, visitors to Boston, Chicago, or Philadelphia get the chance, through the Shop Small Now program, to get a $10 statement credit for shopping at small businesses before July 4th, 2012. You need to spend at least $10 in a single purchase with a registered American Express card.
You’ll need to register for each city separately.
Terms & Conditions:
Limit one per Card across platforms; Cardmembers who have already received a Shop Small Boston statement credit through Facebook, Twitter, or foursquare are not eligible. Registration is limited. Spend $10 or more in a single purchase by 7/4/12. Offer valid in-store at qualifying small businesses in the Boston metro area. Payments using Square are not eligible for this offer. Prepaid and Corporate Cards are not eligible. Offer not valid at government agencies, charities, non-profits, trade associations, shopping property management firms, political, religious or educational organizations, and some franchise locations. Refer to the Shop Small Map and Directory for qualifying businesses. Statement credits are generally issued within 3-5 business days after your qualifying purchase, but may take up to 2 billing periods to post to your account. If your registered Card is replaced during the promotional period, please call the customer service number on the back of your Card for assistance.