Customer VS Guest

The customer is king.

What is the context?

A guest is someone invited to visit (for free).

A customer is a person or organization that buys goods or services from a store or other business, and definitely they are king ...

A guest is customer when they are paying to be at some property. With that said, this guest is king ...

You are correct about the difference between customer and guest. However, "the customer is king" is a common phrase but "the guest is king" is very rarely said.

Since the customer is choosing what to buy while the guest is choosing whether or not to buy, a business would prefer to give the customer freedom of choice (be the king) and not the guest (who may choose not to buy at all).

If you Google the 2 phrases, you will know what I mean. So customer is king would be the "correct" (yang benar) phrase.

We both know the differences between those two, but TS does not.

I agree with you in regards to your sentences. However, if you are involved in hotel business, you would have called your customer as a guest.

I give you an oot example:
A guy parking his car under the sign "no standing" and he got a ticket.
The guy argued and stated that he was not standing; he was sitting in the car.
The guy and the law enforcement can argue about this back and forth a whole day until one of them open a question to what exactly that sign means.

This is why I open my reply post with a question, what is the context or circumstance of this question, before I tell him what is right or wrong.

Common phrase sometimes does not fit with certain circumstances, and, as you said, rarely said doesn't mean this never happens, does it?

True. I assumed he just wanted to know what was the commonly quoted phrase in customer service. In that case, technicalities wouldn't matter.

Admittedly, the question was rather vague. Your answer is probably what he's looking for. I hope the TS clarifies this or is at least satisfied with our answers.

i agree, the customer is king.