The Second Commandment of Sales

The First Commandment of Sales is: Thou shalt never use your cell phone in a meeting with a customer or in a meeting with your boss and, for that matter, when your spouse wants to talk.

The Second Commandment of Sales is: Thou shalt never assume that you know your customer's political orientation or tolerance of jokes.  It's become commonplace to forward jokes and political comment to a group of people on your email list.  I have one word to those reading this:
DON'T
Unless you want your customers to start ignoring your emails.  Resist the urge to forward anything not related to the business.
I was meeting with a customer several years ago with one of my employees.  The customer turned to the employee and said: "Stop sending me those ridiculous emails".  I was embarrassed beyond words.
Your customer may not agree with your views and putting them on the spot like this is not a good idea.  This goes with your colleagues as well.  Resist this urge.  What's funny to you may be offensive to others.