Pay-by-tweet service launched. The incorporation of a foremost payment device into Twitter represents one of the most determined efforts so far to construct ecommerce openly into a social media site. “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 react to an offer for goods or services and make a purchase without leaving the Twitter site, she added. Under the agreement, users who link their Twitter and Amex accounts will be able to accept offers from merchants by tweeting a hashtag built-in with the offer. Provided they also tweet their corroboration to a follow-up message from Amex, the payments company said it would forward their details to the merchant and entire the transaction. Twitter itself will not share in any of the transaction revenue from the Amex transactions, said Ms Berland, adding: “It is all our technology, built on their platform.” Twitter could benefit from the increased advertising surrounding ecommerce, as merchants send out more “promoted tweets” to publicize their offers, according to one person well-known with the arrangement. Twitter was hit by a hacking attack just over a week ago, raising questions about the safety of its platform for payments and ecommerce. Though, Amex said it would not share any of its account information with Twitter, removing the risk of fraud. Ms Berland would not comment on whether Amex planned a similar service for Facebook. The payments company by now has a service there and on other social networks to help merchants endorse offers, though it has yet to add a payment feature to the service.