I absolutely agree that your logic is correct, for a grad student or full-time engineer. But again, early-stage startups != normal business calculus. Look at

I absolutely agree that your logic is correct, for a grad student or full-time engineer. But again, early-stage startups != normal business calculus. Look at it this way: You've got two buckets, one of cash and one of time. You can fulfill business goals by dipping into either or both buckets. The time bucket continually replenishes at a fixed rate but never change capacity, the money bucket may replenish unpredictably in both amount and time and have its capacity expanded (more employees, capital, whatever). If either bucket goes dry, you lose. At an early stage, your cash bucket is near empty compared to your time bucket. If you've spec'ed your business properly (hah) and are not too unlucky (hah hah), you will never have a demand that exceeds the total available amount in the two buckets. So, to fulfill demands, you pull from the time bucket, because it has the greater reserves, and because it'll replenish as every second tics by. As time goes on, though, the demands outstrip what your time bucket can handle. Your time bucket, remember, never gets larger. But, since your business is growing, the cash bucket has been getting larger, and so you start to fulfill demands out of that bucket, using contractors or vendors or whatever. Eventually, you are fulfilling demands entirely out of the cash bucket, because you simply will never have enough time to do them in the required timeline otherwise. The same rule ("gotta fulfill my business demands without emptying my buckets") applies at both ends of a company's lifecycle, but results in entirely different behavior--and that's not bad.