How would you define excellent customer service?

I don’t.

The Guest does. Or the Customer does.

That’s the entire point.

YOU don’t define how well you treat me. I do. The customer. Because it’s MY needs, wants and desires that I’m interested in having satisfied.

Business people think they need to define what excellent CS/CX is, which leads to transactional thinking and definitions, based solely on how they do (or want to do) business and not how the customer lives his life.