I am very keen on Net Promoter Scores (NPS) as a measure. There is a very strong correlation in my experience between companies that are committed to understanding their customers's experience of their business and success. Sounds obvious doesn't it? Yet many businesses don't do this at all or, as the article points out, they do it in a way that misses the point. 

One of the portfolio companies we had when I was at www.dncapital.com was absolutely religious about this metric. They had a mainstream ecommerce business (hence a high volume of transactions and customers), and the founders used to spend an hour a day looking at NPS data. They found that it was the best leading indicator of other issues in their business (tech issues, product issues, stocking issues, logistics issues etc)

One of the reasons we invested in www.pushdoctor.co.uk was because they have always focused on this metric and they have always delivered incredibly high scores. As the articles says, an NPS of 70+ is excellent and 85+ is spectacular. They have consistently been at these levels even as they have scaled rapidly. The Christmas period was a busy time for them, with unprecedentedly high volumes of consultations. The combination of high volume of business and seasonal closure of pharmacies created an issue for some customers. Where do you think they first detected it? That's right. The Net Promoter Scores.