I've often thought that the mantra make something people want should be amended to make something people want to pay for. It's an important distinction. It's the difference between Richard Stallman and Steve Jobs, between Linus Torvalds and Bill Gates. I have great respect for all of those individuals, but I don't look to Stallman or Torvalds for business inspiration. I don't doubt that all YC companies have made something people want, but I wonder whether all have made something people want to pay for.