Twitter (and the Facebook stream) are both a convenient way to casually follow updates from your friends. To understand the need they fill think of what would be the alternative if they didn't exist. Email, chat, and RSS don't really fill that gap.
And yes, this is probably not the kind of thing that you plan. They probably came across it in the course of trying many different things and then realized how powerful it was. A lot of inventions happen that way. That's why I think Google's concept of lettings engineers use 20% of their time to experiment is brilliant.
Twitter grew big because they had two key components. Something that people wanted, and a really good growth channel which is when bloggers started promoting them on their blogs to get more followers. The third component they need to really succeed is a good business model.
And yes, this is probably not the kind of thing that you plan. They probably came across it in the course of trying many different things and then realized how powerful it was. A lot of inventions happen that way. That's why I think Google's concept of lettings engineers use 20% of their time to experiment is brilliant.
Twitter grew big because they had two key components. Something that people wanted, and a really good growth channel which is when bloggers started promoting them on their blogs to get more followers. The third component they need to really succeed is a good business model.