What this number suggests to me is that Tumblr has revenue less than 20 million dollars. I figure:

• about 100 employees
• based in new York
• average $100,000 salary
• 10m annually in humans
• 2-3m annually for office expenses
• 20-30m annually for hosting

Some of these numbers can be up or down, but when I worked at a similar company in New York, we had operating expenses in the same range. (Coincidentally, we had revenue on the same range, and got sold off in a fire sale)