SummaryBox: AmEx, Twitter introduce deals service

DEALS VIA TWEETS: American Express on Tuesday announced a partnership with the Twitter online messaging service that enables card holders to get exclusive deals from participating retailers.

HOW IT WORKS: AmEx card holders who sign up online for the service get the deals by tweeting a Twitter hashtag, or search term, that’s unique to that offer. Savings are automatically credited to the customer’s card statement a few days after the purchase.

PARTICIPATING RETAILERS: Sixteen retailers are initially participating. They range from Best Buy, Dell, McDonald’s and Ticketmaster to Whole Foods Market.