Year: 2

Buyout offer: $2 billion from Facebook, $10 billion from Google

What happened: According to a Fortune magazine piece, the micro-blogging service turned down two billion-dollar offers from Facebook and Google. Many, including Twitter's board, were puzzled by the decision. However, since then, Twitter has raised $800 million in what was the largest venture round in history. Despite its revenue being only in the tens of millions and lack of a strong business model, the four-year-old company is now valued at $8 billion. Sources say it's preparing to go public in 2013.