Maintaining a customer over time is a challenge and there are no shortcuts: product and service are the heart, but they are not enough! It is crucial to be able to seize the unique and unrepeatable "moment" in which the customer is at the height of enthusiasm and is ready to fall in love with your product/brand to lay the foundations of future "reciprocity". Interesting article on how to do that: https://www.helpscout.com/blog/customer-retention-strategies-that-work/