In honor of the Tribeca Film Festival, American Express is running another social media promotion with Twitter. American Express cardmembers who sync their Amex with Twitter and tweet using hashtag #AmexTFF10 will receive a $10 statement credit after making a single purchase of at least $10 in-store at accepting merchants in lower Manhattan by April 29, 2012.

If you aren’t already familiar with these Amex/Twitter promotions, here are directions you can follow to load this offer onto your account:

1. If you don’t already have a Twitter account, create one at twitter.com/signup.
2. Sync your Twitter account with your American Express card by visiting sync.americanexpress.com/twitter. This link will prompt you to sign into your Twitter account and then enter your American Express card number.
3. Log into your twitter account at twitter.com. In the field which says “Compose new Tweet…” enter “#AmexTFF10” without the quotes. This will enroll your card for this $10 offer.
4. You can confirm that you’ve successfully enrolled in the offer by clicking the “@ Connect” link at the top of the page (next to the Home link). It should show a sync notification from @AmexSync, though there may be a slight delay of a few minutes after you have tweeted until the notification appears.
5. Complete your eligible purchase using your registered American Express card, per the offer’s terms.
6. You should receive a notification after you’ve completed your eligible purchase. While statement credits are usually posted within 3-5 business days of purchase, they may take up to 2 billing cycles to post to your account.

The specific terms of this offer, which can be found here, are:

To be eligible to receive a $10 statement credit you must Tweet using #AmexTFF10 then use your synced Card to make a single purchase of $10 or more in-store at accepting merchants by 4/29/12. Offer is valid only at accepting merchants in Manhattan below 23rd street in the following zipcodes: 10011, 10014, 10012, 10013, 10008, 10006, 10004, 10005, 10038, 10002, 10009, 10003, 10010. Limit 1 per Card. Registration is limited. You will be sent a message from @amexsync once offer has been loaded to your Card. Your Card must be synced with Twitter to take advantage of this offer. Payments using Express Pay are not eligible for this offer. 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.

Note: Although this promo was designed for visitors to the Tribeca Film Festival, it appears that enterprising individuals have discovered that purchases of $10 gift cards at the online camera store, adorama.com (which happens to be located in an eligible zip code), have also qualified for the statement credit.