I don't think it's simply "customer service costs money". They have plenty of money and the profit margins to throw more money at it. In startups, the CEO will

I don't think it's simply "customer service costs money". They have plenty of money and the profit margins to throw more money at it. In startups, the CEO will usually step in to do customer service. As it grows, the level of someone doing CS goes down gradually, to business managers, then CS specialists, then the public. I think it's more about humility. The quality of customers also goes down as a business grows bigger.