According to data from eMarketer, Constant Contact and Chadwick Martin Bailey, out of the approximate 20 million-plus U.S. Twitter users, 21 percent follow brands. That’s not such a small number, so brands better pay attention to Twitter. Of the 21 percent of respondents who said they follow brands on Twitter, 36 percent follow 1-2 brands, 28 percent follow 3-4, 16 percent follow 5-9, and 21 percent said they follow 10 or more brands. Why do these people follow brands? The top response at 64 percent was that they were already customers of the brand, and the second most cited reason at 48 percent was to get discounts. It’s pretty surprising that discounts weren’t the number one reason. What’s more is that 50 percent said that they were more likely to buy a brand’s products after following it on Twitter. That means, brands, you better get on top of your Twitter accounts and make sure you are engaging with and rewarding your loyal followers.