Northern Trail Outfitters (NTO) has created a new onboarding series for customers who have purchased its fitness tracker. Customers were automatically opted in and received three emails from NTO within one day. The onboarding series includes personalized recommendations but lacks an easy way to opt out or update preferences.
In this scenario, what best practice was achieved?
(A) Personalized recommendations
(B) Opting customers in automatically
(C) Sending multiple emails in one day
(D) Preventing customers from opting out

Personalized recommendations is the which is grounded on the behavior of the user or the customer. These are the items or the product which have been considered, viewed or purchased from one of the customers who is currently or presently considering.

So, NTO, who established the onboarding series which involves the personalized recommendations of the customer but lacks somewhere, therefore, best practice for achieving in the current situation is recommending personally to the customer.