SAN FRANCISCO - Twitter Inc will seek to raise $1 billion in the largest Silicon Valley IPO since Facebook Inc's 2012 coming-out party, according to an IPO filing made public on Thursday.

The eight-year-old service, the preferred communications tool for celebrities and politicians alike, gave potential investors their first glance at its financials.

Revenue almost tripled to $316.9 million in 2012, from $106.3 million in 2011. It said about 65 percent of its revenue derives from mobile users. But the company has not made a penny in profits since 2010.

The service had 218.3 million monthly active users, on average, in the three months ended June 30. Three-quarters of its monthly active users are considered mobile users, it said in the filing.

Twitter intends to list common stock under the symbol "TWTR."

Here are some facts about the micro-blogging site:

Created: 2006

Headquarters: San Francisco, California

Founders: Jack Dorsey, Evan Williams, Biz Stone, Noah Glass

Chief Executive Officer: Dick Costolo

Active users: Over 215 million monthly active users worldwide. By comparison, at the time of its 2012 IPO filing, Facebook had 845 million active monthly users worldwide, including 161 million active monthly users in the United States.

2012 Revenue: $317 million in 2012 and $254 million for the six months ended June 30 this year. The company, which has not been profitable since 2010, reported a net loss of $69.3 million for the six months ended June 30. By comparison, at the time of its IPO filing, Facebook earned $1 billion on prior-year revenue of $3.71 billion.

Average revenue per user: The company did not provide this figure in its filing. According to Reuters' estimates, it came to 64 cents per user in the second quarter.

At the time Facebook went public, its average revenue per user in the first quarter of 2012 was $1.21. As of its second quarter in 2013, it was $1.60.

Number of employees: 2,000 as of June 30. By comparison, at the time of its IPO filing, Facebook had 3,200.

Biggest shareholder: Co-founder and former CEO Evan Williams. By comparison, Facebook's biggest shareholder was its founder and CEO Mark Zuckerberg.

Time spent on Twitter: 4.2 hours a week in the United States, according to research company eMarketer. By comparison, Facebook users spent 7 hours a week in the United States and about six hours a week on the site worldwide.