The first "pay-by-tweet" service has been launched on Twitter, with American Express introducing a service on Monday that lets its cardholders buy products simply by sending a short message.
The integration of a leading payment mechanism into Twitter represents one of the most ambitious attempts yet to build ecommerce directly into a social media site.
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"We're turning a tweet into an actual transaction," said Leslie Berland, head of digital partnerships and development at the payments company. For the first time, Twitter users will be able to respond to an offer from a merchant and make a purchase without leaving the Twitter site, she added.
Under the arrangement, users who link their Twitter and Amex accounts will be able to accept offers from merchants by tweeting a hashtag included with the offer. Provided they also tweet their confirmation to a follow-up message from Amex, the payments company said it would forward their details to the merchant and complete the transaction.
Ecommerce has been slow to take off on social networks, with retailers who have tried to use their presence on Facebook to stimulate transactions reporting disappointing results.
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Twitter itself has tried offers, known as "Twitsclusives", through which merchants issue discount codes to users that they can use when shopping elsewhere, though these have not been widely adopted.