This is something I find highly amusing: on the wiki page for Twitter, it says:
"The Industry Standard has remarked that Twitter's long-term viability is limited by a lack of revenue..."
Only in the Internet age is an income considered optional for a business! Too friggin' funny. This is like saying: "Joe Blow's long-term health outlook is limited by his refusal to eat or drink anything".
The Financial Dictionary says: "When evaluating stocks, revenue growth serves as an indication of a company's health."
But in the Internet age, it's apparently entirely incidental to the stock value! Nut city.
How they plan to become profitable? By displaying ads, or rather sponsored tweets.
Mind you, this is all over the net. It was covered by pretty much every newspaper when it was announced in April.
Aha. After 40-something years, it finally bites me in the ass that I don't read news. Thanks, dude.