I received a Gillette razor in the 1990s for my 18th birthday. I have been buying replacement blades ever since. Even when I upgrade to a new razor I still stay with the brand.
Big Data and personalization are not a new trend. Local stores have been personalizing their messages since they were created. When a big brand can reach a person at the right time and with an authentic message the relationship can last decades.
As Bezos and his minions get ever better at cracking personalization, brands and retailers will have to work even hard to keep data fresh and their message authentic.