On Twitter, users who subscribe to other users' tweets are known as followers. As a social microblogging site, Twitter revolves around the principle of followers. When you choose to follow another Twitter user, that user's tweets appear on your main Twitter page. If you follow 10 people, you'll see a mix of their tweets scrolling down the page. To become another user's follower, simply click on the Follow button in that person's tweet. By clicking on the "Followers" link on a user's profile page, you can see everyone who is following the person.

Followers are becoming an important advertising channel as messages can be broadcast to a large number of users quickly. This is one reason many Twitter users work hard to acquire followers, some even offer to buy them.