Here is are the 33.5 Core Principles of Customer Service. It's their friendly people. All things being equal people want to do business with their friends. All things being not quite so equal, people still want to do business with their friends. They need answers, orders, service and information.
Memorable service leads to positive word of mouth advertising and repeat business.
Word of mouth advertising is 50 times more powerful than advertising. Word of mouth advertising is the most powerful form of advertising known to mankind. The difference is that math is based on logical solutions and serving people is based on emotional solutions. You must self-study what you never learned in school. There is a logical and emotional side of serving the customer.