You Can't Please Everybody
Some people like to complain for the sake of complaining, but you still have to listen to them.
Your ability to address individual issues, word for word and head-on, shows customers that your company does care. This can make a big difference in both retaining customers and marketing to them for the long-term. Sure, you'll encounter an irate visitor or two who simply likes to complain. Or you'll receive long diatribes that aren't necessarily focused or clearly related to your products or services. Read them anyway for the minor gems they may contain.
Excerpted from 101 Internet Marketing Tips For Your Business