NEW YORK  >> Twitter is taking its users shopping.

The short messaging service began testing a "Buy" button Monday that lets some of its users make purchases or donate money to charities without leaving Twitter. Initial partners include music stars Eminem and Brad Paisley, retailers Home Depot and Burberry and nonprofits The Nature Conservancy and GLAAD.

After clicking the "Buy" button, users are asked to enter their address and credit card information. The order is then sent to the merchant for delivery. The company said in a blog post that users’ personal information will be encrypted and saved on Twitter so that they can buy things again without re-entering their information.

The shopping feature comes as the San Francisco-based company tries to increase its user base and revenue, most of which comes from advertising. It had 271 million average monthly users at the end of June, up 24 percent from a year earlier.

Facebook, which has more than 1.3 billion users, started testing its own "Buy" button in July.

Twitter’s button is only available now for a "small percentage of U.S. users," but the company said that will increase.

The shopping button could help Twitter add another source of revenue as the digital advertising market and online shopping grow. Twitter did not offer financial details about its new service and did not respond to a request for comment.

Research firm eMarketer estimates that Twitter will account for 1.6 percent of digital ad spending in the U.S. this year, up from 1 percent in 2013. It is expected to hold 3.5 percent of the mobile ad market in the U.S. in 2014, according to eMarketer.

Twitter Inc. shares rose $1.30, or 2.6 percent, to close at $52 Monday.