Since last year, Amex Sync has let American Express cardholders earn discounts in return for posting tweets including hashtags about certain products, and now it's letting them buy things just by tweeting special hashtags.

ENGADGET

American Express (Amex) has launched a purchase-by-tweet service for its US-based customers.

BBC: American Express launches purchase-via-Twitter service

Gemalto (Euronext NL0000400653 GTO), the world leader in digital security, announces that its UpTeq NFC high-end SIM has obtained certifications from the three largest global payment networks - American Express (AMEX), MasterCard and Visa, in addition to previous certification by EMVCo.

ENGADGET: Gemalto adds AMEX, Mastercard and Visa certs to its UpTeq NFC SIM

It was 1963, and a scandal involving fake inventories of salad oil at a small subsidiary of American Express drove down the price of Amex shares.

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Citibank and Bank of America now offer American Express cards, the result of an antitrust lawsuit AmEx won against Visa and MasterCard in 2005.

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The American Express Centurion card, also known as the "Black AmEx, " is the subject of much speculation on Internet chat rooms.

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American Express invites financial institutions to issue cards carrying the signature American Express logo and also to act as merchant acquirers on the Amex network by leveraging its infrastructure and brand image.

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