Depends on the software but its easy to overlook. I'm just a solo dev, so every hour I spend on customer support is an hour I'm not doing product development, m

Depends on the software but its easy to overlook. I'm just a solo dev, so every hour I spend on customer support is an hour I'm not doing product development, marketing or generally something that is a leveraged use of my time. For customers who pay less, that time is even less leveraged. Also, for customers who don't have a strong command of english there's translation work, misunderstandings in customer service communications that are more likely to happen, pressure to provide documentation in multiple languages...all very time consuming and thus disproportionately more costly if you are doing that work with less margin flowing back.