1. Thinking your customers are dumb:  If you believe that your customers are dumb, then what does that say about your business?  Instead of making them feel dumb (and if you believe they are, they can sense it), see the positives each person brings to the table and educate them on what they need to know.  For instance, if you are a graphic designer, give your customers a 10 page booklet on what makes a great logo.  Not only will they seem smarter, but they will see you as an expert.
  2. Being disrespectful:  Is there anything more disrespectful than when you schedule a time with the cable guy, plumber, etc. and they are late?  They are essentially telling you that their time is more important that yours.  Respect your customers.  Be on time, be polite and even better thank them for their business!
  3. Being Nit Picky:  If you have a 30 day return policy, and the customer returns their product on the 32nd day, just give them their money back and thank them for their business.  Don’t take it back and say “I can refund your money this time, but next time I won’t be able to.”   And even worse, don’t argue over your policies.  Both will leave a bad taste in their mouth.  When they need your services again, they will be sure to look elsewhere.
  4. Becoming a pushy salesman:  We all hate going to a used car lot.  And I hate furniture shopping.  These are places where salesmen are constantly trying to sell you stuff, whether you want it or not.  You are not a person to them, you are a dollar sign.  No one likes to be sold something, but we all love to buy.
  5. Frowning:  Truly, few things are worse than approaching someone who looks like he is mad at the world.  I’m not saying that you won’t have bad days, we all do.  However, when possible, make sure the employees that are the most positive and upbeat are those that are customer facing.  Smiling goes a long way in making a positive connection with your customers.  Your customers are more apt to buy from businesses they like.

As always, I would love to hear your thoughts.  What are some other dumb ways to kill a business?