Fire your bad customers
I've had fun replying honestly to bad customers. I run a service where you pay once for a lifetime upgrade, and it doesn't make much money so I don't care very much about dissatisfying bad customers.One of them emailed me with a subject line of "my account is broken! FIX IT!!!" and no body, to which I replied "how rude, do you think I'm your slave?". He replied in the same vein, saying that if I didn't fix it he'd go to a competitor, to which I said "it's a one-time payment and you've already paid me, if you leave you're just basically saving me time in support".He replied a few hours later apologizing for his rudeness and detailing what the problem was, which I helped him fix, but it was fun to see how much customers expect to be able to walk all over customer service and how surprised they are when you don't take their shit.To be fair, 99% of support emails are very kind and polite.