With new services and acquisitions, social media giants Facebook and Twitter are entering the online sales market. Their goals are to let people shop while chatting and sharing posts with friends. Facebook, with more than 1.2 billion users, tried enabling purchases on its social network in the past, with limited success. Twitter and Amazon.com Inc., the largest online retailer, rolled out a joint service last month that lets members shop by hashtag.

As online competition between the sites grows, the social media platforms are betting that goods and services displayed alongside posts and tweets will lead to impulse purchases. These purchases will give retailers and advertisers an added opportunity to boost sales. Facebook is testing a “buy” button on browsers and mobile devices that lets users make purchases through advertisements. Separately, Twitter said it acquired CardSpring Inc., a service that lets users redeem deals and discounts through merchants’ tweets.

Twitter’s acquisition of San Francisco-based CardSpring is a major move by Nathan Hubbard, the former president of Ticketmaster, who was hired by Twitter to find ways to let people buy goods directly from tweets. Twitter CEO Dick Costolo said the goal of the social network is to offer “commerce in the moment.” CardSpring lets people claim coupons or special deals via tweets. However, it won’t enable the direct purchase of products. The exact terms of the deal have not been disclosed.

Facebook’s new “buy” button service is being tested in the U.S. with a few small and medium-sized businesses, despite saying earlier this year that direct purchases are not the best strategy to serve social media markets. “We don’t have any plans to go into the direct e-commerce market because the advertising products we provide, I think, are the best thing we can provide to help grow this market,” CEO Sheryl Sandberg said in January. Security and privacy are also a paramount concern. Users’ credit or debit card information will remain exclusively with Facebook and will not be shared with other advertisers, the Menlo Park, California-based company said.