Facebook hit a mighty milestone this September, says Zuckerbeg. It reached one billion monthly users. Active users too, he adds - a salient point, given the furore over the number of dormant or fake Facebook accounts. Zuckerberg didn't confirm, however, whether the billion includes duplicate accounts - people who have one Facebook for friends, one for work and so on.
'Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in my life,' he wrote. '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.' 590,981 people have since 'Liked' his post.
To celebrate the occasion, Facebook has also created its first marketing video. A rather odd creation that likens Facebook to 'chairs', 'doorbells', 'basketball', and - in a clip redolent with cult messaging - 'a great nation'. You can watch the video by subscribing to Zuckerberg's timeline.
Zuckerberg must be delighted to finally have some good news to celebrate. It's all been rather gloomy over at Facebook HQ over the past few weeks, what with the share price dropping to half its original $38 value, and Zuckerberg's own personal fortune dwindling by a sizeable $8.1bn...
Still, with Facebook users recording some 1.13 trillion Likes, 140.3 billion friend connections and 219 billion shared photos since the network launched in February 2004, Zuckerberg can rest easy that there's still life in Facebook yet.