Can we unpack customer relationships a bit? First how were they defined in those elasticity studies, which elements of the marketing mix are included here and how that translates to products vs services?

Unless you have specific data for a specific company, you can't really do that unpacking across the marketing mix. But what we do know is that it is a very strong effect. If you have a purchase today, let's say $200 with a 50% gross margin. You just made $100 from that customer. And if your loyalty rate is 80%, excluding the time value of money, you can pretty much multiply your short term number by five and that's just the value of the relationship because you're getting $100 now and then an expected $400 spread over the future. But if your loyalty rates were to go from 80% to 90%, your $100 customer is now worth $1,000. Even though there's only a 10% increase in loyalty, it doubles the value of the company.