The point is that each customer journey is its own unique story. From the supermarkets point of view when they look at the sales at the end of the day they will see my transaction amongst the thousands of others but they won’t know my story. Even if I got a prompt on my receipt to fill out a survey to enter a prize draw and I went and gave them an NPS rating, would they know any more about my customer story?
http://customerthink.com/evolving-customer-surveys-into-customer-stories/