On: Facebook has 1 billion monthly active users

[kanzure]

> What will be the second site to hit that landmark, does it even exist yet?

http://en.wikipedia.org/wiki/Tencent

"As of December 31, 2010, there were 647.6 million active Tencent QQ IM user accounts,[1] making Tencent QQ the world's largest online community. The number of simultaneously online QQ accounts has sometimes exceeded 100 million.[7]"

Definitely beats gmail's 425 million.