You guys are forgetting one very important thing here.
Sure, 20% of your customers create 80% of your problems. However, you can't just "dump" those 20% of your customers and free up 80% of your problem.
Here's the reason - we're online! The moment I lose my cool with a customer, and politely tell him/her the order is being cancelled, you can buy some place else, what do they say?
"I'm going to bash you online".
"I'm going to post on every forum".
I had a customer who bought an item and even before he contacted me, he already contacted the BBB and posted on his forum how upset he was over a product he purchased from me. This isn't a product I made, but rather resold. Instead of contacting the manufacture, or contacting me, he made it his mission to make sure no one ever purchased that product again because he didn't like the product.
Not very fair. Plus, the only thing missing from his package to make him happy was a 45 cent bracket that the manufacture forgot to include.
How can you reason with people like this?
People like this ruin my whole day.
This is why you need time off ;)