It’s really interesting to see how twitter started up and the users was really the initiators of the new features that consist today’s twitter. First of all, the twitter project was started up as a side project. This means that even the founders of this great service hadn’t a clue of what twitter could become one day. They simply started it up with a minimum aspect of functionalities. For example the @ was firstly used by some users they simply wanted to reply to other users tweets. Later on, creators of tweeter just implemented additional functionality that could help people use the @ symbol when they needed to reply to someone.