"Inconsistent Hiring Quality"<p>I think that one of the prime sources of this mistake is the assumption that adding another person will necessarily increase output.<p>The hiring criteria that is being applied at my current day-job employer seems to be "Will X be able to get anything done?" which doesn't even come close to guaranteeing that the hire is a good investment, even if the company is established and can afford to wait a while for a new hire to mature. At a startup, the situation is obviously even more critical.<p>Time and time again I've seen weak new hires suck up not only the time, but the morale, of highly productive existing employees. Good hires come much closer to training themselves, and having a great new person around makes other folks happier.