Ask HN: 300 employees, what is Twitter doing with them all?

Twitter just announced their 300th employee [1]. I thought I would extend the question to people who might know. What is a company like Twitter doing with 300 employees? Of course this is all speculation, but I feel 300 is just too much.

I would love to hear what everyone here thinks!

[1] https://twitter.com/#!/twitter/status/28816319556