Go talk to some folk in retail - they'll disagree ;-)
Conversion funnels. Split testing. All happened in retail long before all this new fangled on-line nonsense. In fact retail optimisation is fascinating stuff. It's a few years old now but 'Why We Buy: The Science Of Shopping' by Paco Underhill is a great read.
If you ever get the chance to chat to folk who do data mining for store chains do so. They have fascinating tales to tell.
Indeed, I've heard they tried using nfc's on customer baskets to track their movement around the store and see where they stop and for how long.
Very interesting.