Twitter is stepping up its ecommerce capability with tests in the US of a "Buy" button.
Today we are beginning to test a new way for you to discover and buy products on Twitter. For a small percentage of U.S. users (that will grow over time), some Tweets from our test partners will feature a “Buy” button, letting you buy directly from the Tweet.Twitter Tests "Buy Button With Selected U.S. Partners [blog.twitter.com]
We’ll be starting the test with a group of artists, brands, and nonprofit organizations,
Earlier
Report: Twitter Shopping "Buy Now" Button Appears In Tweets [webmasterworld.com]