We all know that, given the availability of hosted software and cloud options, going around IT is easier than ever. So how can we make sure that our IT service customers become our biggest fans and start to think of IT as irreplaceable?Over the years I've tested various ways of measuring customer satisfaction, but they tended to be overly complex and therefore rarely used. I have tried face-to-face interviews, online surveys and post-project questionnaires. But none of my customers seemed really interested in any of these. Then, a few years ago, I read a Harvard Business Review article that described the only metric we will ever need. In this article, Fred Reichheld introduced the concept of the net promoter score (NPS). The NPS is derived by asking customers how willing they are to recommend products and services to their friends, families and co-workers. When I first heard about NPS, I thought to myself, "Nice idea, but it probably does not apply to IT." I just could not imagine someone telling their friends about the wonderfulness of an IT department they are forced to use.Then I started thinking about Buff. Buff is my car mechanic. Buff just might be the greatest mechanic on the face of the earth. I don't make a car-related move without Buff. Buff is scrupulously honest. Some years ago, Buff replaced my front brakes. About 40,000 miles later, the brakes were making noise, so I took my car back to Buff and asked him to check out the problem. He called me later that day to tell me I needed new brakes. He then asked me, "Didn't I already do those brakes?" Yes, I told him, but that was around 40,000 miles ago, so it was time for a re-do. Buff paused for a moment, then said, "Those brakes should have lasted longer than 40,000 miles. I'll replace them, but I won't charge you for the work."I am pretty sure that Buff has no idea what an NPS is, but I suspect he has the highest NPS in history. I tell everyone I know about Buff. Everyone I know tells everyone they know about Buff. People I don't know call me to ask for an introduction to Buff.The EpiphanyWhat does this have to do with using NPS for IT? Thinking about Buff's NPS caused me to actually spend some brainpower on how I could apply NPS to IT. At first, I struggled with how to apply the metric in an environment where we have a monopoly over our customers. I grew frustrated. Then, the epiphany came. How about tweaking the standard NPS question like this: "If you had a choice, how likely would you be to use us for your next IT project?"I have been trying out my IT version of NPS for about a year, and it works really well. This one question does not take much time to ask\u2014or to answer. In asking the question, we emphasize the "if you had a choice" part so our customers give us an answer based on their experience with all types of product and service providers. This is not perfect, but I gave up on finding the perfect metric a long time ago.For example, we recently asked this question and learned that our production release process was causing incredible chaos for our university's enrollment department. We improved how we communicated the pending changes, and now the enrollment department thinks not only that we know what we are doing but also that we care about their needs.We track our NPS results and use them to change our actions and behaviors to create fans that rave about IT. NPS helps us become, in the minds of our customers, irreplaceable.Niel Nickolaisen is CIO at Western Governors University, an accredited online university based in Utah.