What do you consider excellent customer service? I truly believe that customer service is like beauty - it's in the eye of the beholder. One size does not fit all.
Let me quickly take you through a visit at an average Joe-type restaurant....
I arrive and a host gets me seated in a timely manner. My server is at my table almost instantaneously; introductions made, specials cited and drink order taken. After drinks arrive, my food order is taken and placed. I receive my food quickly and its hot. My server checks on me once after food is delivered (bonus points if my server actually delivered it) and keeps my glass full without me asking. The offer of dessert is made and the check is delivered shortly after. The server was fast, prompt, friendly and left me alone. I didn't have to wait, I wasn't bothered while I was eating and all my needs were met without asking. They would get at least a 20% tip.
Now you might be thinking, isn't that how all service should be at a restaurant? I would reply, yes. There are some places that do too much to win customer over and that grinds my gears. I don't want 3 managers to stop and ask how I'm doing. I don't want the server to make small talk with me or stop by 7 times. I'll flag you down if I need you. However, some people like all that attention when dining. They like to chat with the server. The extra attention doesn't mean a fail in my book, but that extra aggravation make not have tacked on extra tip money for the server.
I believe that a person in a service industry should set a standard level of customer service they know they can provide (or be provided with one by the company they work for). From there, tailor the experience to your customer. Learn how to read people. Are they rushing you? They may want fast, to the point service. Do they ask you how your day was? Small talk may be permitted. Customer service is just that, for the customer.
The world of real estate is no different. Realtors have more expectations to meet but more prep time to establish needs and wants with their customers. Every real estate client gets some one-on-one time with me. Not just to see how many bedrooms and baths they want/need, but to evaluate how they want/expect the transaction to go and what we expect of each other.
How else does someone WIN with you?