They make a ton of revenue....

  In order to increase the value of the company, Basecamp has decided to stop 
  generating revenue. “When it comes to valuation, making money is a real 
  obstacle. Our profitability has been a real drag on our valuation,” said Mr. 
  Fried. “Once you have profits, it’s impossible to just make stuff up. That’s 
  why we’re switching to a ‘freeconomics’ model. We’ll give away everything for 
  free and let the market speculate about how much money we could make if we 
  wanted to make money. That way, the sky’s the limit!”