One billion people - a seventh of the world's total population - are now using Facebook every month.
The milestone was marked by hoodie-loving founder Mark Zuckerberg on his own Facebook profile.
"This morning, there are more than one billion people using Facebook actively each month," he wrote. "If you're reading this: thank you for giving me and my little team the honor of serving you.
"Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in my life. I am committed to working every day to make Facebook better for you, and hopefully together one day we will be able to connect the rest of the world too."
Zuckerberg and his "little team" (now a staff of more than 3500) also released a brand video to mark the occasion. It centres on the notion that Facebook has become as important a tool to meeting people as other everyday things we take for granted - such as chairs, doorbells and aeroplanes. Like?