American Express has experimented with things like Twitter- or Facebook-based discounts, but now it's gone one step further: customers who have linked their American Express accounts with Twitter can now directly buy products with their tweets. Starting today, the credit card company will be periodically rolling out deals, including a discounted Xbox 360, Kindle Fire HD, and $25 Amex gift card, then letting users buy them by tweeting hashtags like #BuyAmexGiftCard25. Amex will ask the user to confirm in another tweet, then ship it to the address on record and charge their card — assuming they've previously added Twitter integration and a shipping address through Amex Sync. Each deal will last for three weeks.

The idea of linking a Twitter account to a card isn't new. In early 2012, the company started letting people post tweets and receive discounts in return; if they tweeted a hashtag for a company like Whole Foods and then made a purchase there, they'd automatically receive a partial credit on their purchase. The results here are functionally similar, but you're not just doing some advertising in exchange for credit — you're putting an actual purchase history online and asking American Express to charge your card through Twitter.