Jeff Bezos, the CEO of Amazon, once said, "The best customer service is if the customer doesn't need to call you, doesn't need to talk to you. It just works."
In other words, the best customer service is invisible. It just happens. The customer doesn't have to ask for it. It just gets done the way it's supposed to. What does get done isn't always noticed, and shouldn't be. Invisible service means it happens without you ever seeing it.
The short version of the story behind the Bezos quote is that he didn't feel it was necessary to put contact information on Amazon's website. He felt that if Amazon did what they did, as well as they did it, the customer would never have a reason to call. There shouldn't be a problem. And, that works… until there is a problem. Amazon may be flawless on their end. But, then they turn the customer's package over to FedEx, UPS, or the USPS for delivery. What happens if the package gets lost or there is a weather delay? Is that Amazon's fault? No, it's not. But, to the customer, it appears to be that way. So, who does the customer want to contact? Amazon. They realized that very quickly. And now, it's very easy to reach someone on customer support.
Let's take a less obvious example. You never see what goes on behind-the-scenes. That's why they call it "behind-the-scenes". For example, you probably have no idea all the steps in the process of how your checked luggage ends up at your destination. And, you don't really care. If it shows up, on time, the way it's supposed to, it's a non-event. You never notice because that's just what you expect.
But, if the bag doesn't show up… you notice. If someone "behind-the-scenes" doesn't do what they are supposed to do, and the bag ends up in the wrong city or never makes the flight at all, you notice. In other words, what doesn't get done, or what gets done incorrectly, gets noticed.
The phrase "conspicuous by your absence" comes to mind here. You're so used to something that you don't even notice until it's no longer there.
Yes, the best service may be invisible. It goes unnoticed. It just happens the way it is supposed to until it doesn't happen. The absence of good service, which always seemed to happen, becomes obvious and gets noticed immediately.