Making cash: what is Twitter doing?

Link to the article: Channel 4 News

By Benjamin Cohen

The microblogging site Twitter goes offline with Twestival Local, hundreds of events around the world bringing Tweeters together to raise money for charity. But can Twitter make money for itself?

It is one of the world's most popular websites, allowing people to send instant messages to online followers and friends.

But despite the increasing commercialisation of its service Twitter itself isn't making any money and still has no revenue stream of its own.