YouTube has proved beyond all doubt how much of a real hit the video sharing site has become.
One billion people around the world use it every month, watch everything from clips of cute kittens to scenes of social unrest.
The figure marks another step in YouTube's evolution from a quirky startup launched in 2005 to one of the most influential forces in today's media landscape.
It has given YouTube's owner, Google, another lucrative channel for selling online ads beyond its dominant Internet search engine.
- Google bought YouTube for £1.1 billion in 2006 when the video site had an estimated 50 million users worldwide
- Over 4 billion hours of video are watched each month on YouTube
- 72 hours of video are uploaded to YouTube every minute
At the end of 2012 Google celebrated the first video to be viewed a billion times, PSY's Gangnam Style.
Singers including Justin Bieber were also discovered on the site.
Here are some of YouTube's most popular videos of all time: