Twitter signed a deal with Amazon.com to let users shop directly from posts on its microblogging service, part of a push to add e-commerce options for advertisers.

When product links appear in a tweet, U.S. customers can add the items to their Amazon shopping carts by replying to the post with the hashtag AmazonCart, the companies said Monday in a statement. While Twitter won't get a cut of individual sales, Amazon will increase spending on Twitter advertising products, said a person with knowledge of the matter, who asked not to be identified because terms aren't public.

Twitter has been seeking to woo advertisers and retailers by adding tools to help them reach its 255 million users. By enabling e-commerce, Twitter is aiming to keep consumers on its site for longer and learn more about their interests and shopping habits -- valuable information for advertisers, which contribute the bulk of the company's revenue.

The company has been exploring adding direct shopping options on the site, and last year hired former Ticketmaster executive Nathan Hubbard as head of commerce to bolster its efforts. In an interview last week, CEO Dick Costolo said shopping on the site would have the same real-time feel as the rest of the Twitter experience.

"I think about our commerce opportunity as commerce in the moment," Costolo said after the San Francisco-based company reported earnings.

Julie Law, a spokeswoman at Amazon, declined to comment on the terms of the deal, as did Jim Prosser, a spokesman for Twitter.