Digg isn't a startup. It started in 2004 and has been mature for about 5 years. They are a business now. And a big one at that.
Unless you are owned by a larger company that runs you at a loss as part of their strategy. Or stragedy.
Evidently Digg is better at the monetization game than Reddit has been, so more sales staff I can understand... but devs?
Personally I have no idea nor do I see any reason for that many people working for digg, but my understanding is that Digg (or rather Kevin Rose) has always been about having the perception of big without actually being that big.
Personally, I don't consider Digg a startup.