According to Sotheby’s International Realty, Twitter is “part instant messenger, part blog.” Twitter allows users to make short, “bite size” statements called “tweets”—under 140 characters—making it a quick and easy way to reach a wide audience. A Twitter profile is simple and direct, containing only a short bio and main URL, a profile icon and a background image. With Twitter, users “follow” the author’s profile in much the same way they “friend” on Facebook. With Twitter you can be “hyper-connected” to your “followers” (a.k.a. your friends)—so you always know what they’re doing—or you can stop following them at any time. You even can set quiet times so you’re not interrupted.

Twitter was designed as a free social networking service for family, friends and colleagues to stay connected through the exchange of quick, frequent answers to one simple question: “What are you doing?” Say you’re running late to a meeting… your co-workers might want to know. Or you’re at a great party and want to invite your friends: Twitter’s real-time updates can be useful in a variety of situations. Recently, following allegations of fraud in the Iranian presidential election, protesters used Twitter as an effective rallying tool to communicate the time and location of demonstrations.

Since its 2006 launch, Twitter has gained enormous popularity as a personal and professional communication tool. In February 2009, Twitter amassed a unique audience of 7 million, an increase of more than 2.5 million from January 2009, according to a March 19 article in the Wall Street Journal.

The higher the count of “followers,” the more audience a profile commands by “tweeting” or posting frequent and relevant messages. These actions begin to snowball, growing the profile’s Twitter presence and reputation. Politicians, celebrities, and businesses are increasingly employing this smart and savvy tool as a simple and effective method of free viral marketing.