Social networking site Facebook said today that its user base now comprises over 250 million people around the world.

While the announcement post by founder Mark Zuckerberg isn’t especially compelling (it reads like a rather un-compelling corporate announcement), the interactive visual timeline of membership growth to that quarter-billion number is worth a look.

It’s interesting to see the growth flow, out of the US to the UK then spreading into other parts of Europe, the Middle East and other regions in the world.

Here’s one way of interpreting what the growth means, from Digital Beat:

[…] Facebook says that 70 percent of its users are outside the US. […] Facebook does have a strong presence in other advertising-rich countries, like the UK and Canada. But it is growing in internet-connected places around the world (judging from the map, mainland China’s growth is especially surprising to see). In order to monetize all of its users in the foreseeable future, the company is experimenting with more forms of virtual goods and currencies. Its virtual gift store has been around for years, and is reportedly bringing in good money, but now it is rolling out a virtual payment system for developers, and letting users pay in a variety of currencies.

Just over 3 months ago, the user number was 200 million. So 50 million more users in that very short time.

An ever attractive-looking marketing platform.