Customer Post Purchase keep up the relationship after the 1st month with personalized communication.
Onboarding after the first month needs to be as personal and customized as possible.
Use the metrics and data you have to create targeted offers
Segment your customers into different lists.
Personalize your communication with info you have on your customers.
Celebrate customer milestones. These are some of the ways to have a deep relationship with your customers. Your current customers will buy from you again and again if you have a good onboarding process after purchase.