NY Times has a great article on small businesses using Twitter to increase sales:

For many mom-and-pop shops with no ad budget, Twitter has become their sole means of marketing. It is far easier to set up and update a Twitter account than to maintain a Web page. And because small-business owners tend to work at the cash register, not in a cubicle in the marketing department, Twitter’s intimacy suits them well.

“We think of these social media tools as being in the realm of the sophisticated, multiplatform marketers like Coca-Cola and McDonald’s, but a lot of these supersmall businesses are gravitating toward them because they are accessible, free and very simple,” said Greg Sterling, an analyst who studies the Internet’s influence on shopping and local businesses.