Twitter is a fairly new kind of social networking site that allows what has become known as 'micro blogging'. Users can send short messages to other users and to the Twitter website through a number of different outlets. The most distinctive aspect of Twitter is that messages are limited to 140 characters in length. While this does limit the detail that can be sent in a message, or 'Tweet', it means that users can receive updates through the Twitter website, SMS, instant messaging, RSS or email. Twitter was launched in March 2006 by start-up company Obvious Corp. From a marketing point of view, it has uses in customer service, ecommerce and mcommerce marketing, and affiliate marketing. A number of companies, large and small, are using Twitter to keep their customers up to date about their products and deals. Amazon has been using Twitter successfully to keep customers posted about new products and special deals.