Four days after it went live thefacebook.com had just 650 users. Just nine months after the launch, it had nearly one million active users. And less than a year later it changed its name to simply Facebook.com.
Discover how other famous companies got their names
Since 2013, Zuckerberg decided he’d only take home a $1 (77p) salary each year. His reasoning? He’s said he’s made enough money already. But don't feel too sorry for him. He raked in $23 billion (£17.9bn) in 2017 from share options.
Zuckerberg has it written into his contract that, should he die while still running the company, the control may be transferred to a person or entity that he has chosen as his successor.
Find out why Mark Zuckerberg is one of a number of billionaires giving away their fortune to save the world
After 15 years Facebook is still looking to grow. It has recently revealed that it plans to merge its apps in order to develop "the best messaging experiences". The idea of connecting Facebook Messenger with WhatsApp and Instagram messaging has shocked many who see it as posing a risk to privacy, but Zuckerberg has said that the merger is in the early stages and the earliest it could actually happen is 2020. Here's to the next stage of our Facebook lives...