Not only will it get you repeat business, but it'll get you referrals too, and referrals are way easier to convert into paying clients. Referrals not only trust you from the get-go because they heard about you from someone they trusted, but because they know you conduct yourself as a professional.You'd think it is common sense, but that is too uncommon these days. You don't have to deeply love your customers, but you definitely should care for them. A one time sale is pretty easy to pull off, but reputation carries a long way and a good one will help you get repeat business.
Calling customers names or not taking their issues seriously (even if you feel they are not issues) will not make you successful
While this thread was geared more toward sellers of this forum, I think the advice is general enough to be applicable anywhere.This is great advice. I'm constantly seeing butthurt sellers on the Amazon forums. The worst is when the seller replies with a snarky comment.