The story I often tell as an example of word of mouth ambassadors I call the "Philadelphia Story":
I was in the Philadelphia airport several years ago and I was wearing a Kinloch Golf Club logo. A man I had never seen before approached me, half-gestured at the logo and asked me if I was a member. I replied that I was not but had the pleasure of working with the staff, particularly in the shop. The fellow introduced himself and began his "Then you will appreciate what I am about to tell you" story.
When you resolve problems to the satisfaction of these customers, they will become your loyal, staunch supporters, and they will spread positive word of mouth advertising for you. It’s human nature. We respect people that admit mistakes, and correct the situation. We give them the benefit of the doubt in the future, and we tell others that they fix their mistakes and keep their promises. It leads to great customer loyalty. If you really want to stand out, go in search of the unhappy customer that never complained. If you really want people to say great things about you, find and fix the problems that the customer didn’t identify. Ask for feedback from your customers, and follow up. You will win customers and friends; and they will actively influence other people with their positive recommendations about your facility.
Finally, take the time and give careful thought to taking care of your ambassadors and remember it doesn't hurt to ask for references. Give additional discounts for each reference, a free service, special treatment, and don't forget the occasional gift to better customers. People will recommend you if they believe in you and your staff, and a little perk always help remind them to tell the story.