Social networking site Facebook will touch one billion users by 2012 and the fastest growth is coming from Brazil, with Facebook picking up another 1.9 million users in May, according to statistics site Social Bakers.

Currently, there are more than 700 million users worldwide and other fast growing social networking countries include Indonesia, Philippines, Mexico and Argentina, the report said.

Last July, when Facebook reached the 500 million mark, its founder Mark Zuckerberg said there was 'no chance' the company wouldn't reach one billion.

It is almost a guarantee that it will happen. It will be interesting to see how it plays out, Zuckerberg said that time.

According to Businessinsider.com, the company currently has an estimated valuation of US$80 billion.