Once you have acquired a customer, you will have made what is called a “front-end” sale. You have now started a customer relationship that provides you with future opportunities to cross-sell and up-sell that customer with additional products and services. This a repeat of your nurturing process but with a new contact (email) sequence focussed on your next “back-end” sale. A good term for this on-going process is called the “lifetime value of a customer” because it refers to all future sales you make to this customer, not just the next one.
While customer retention and growth through up-selling and cross-selling are the primary goal at this stage, new prospective customer referrals and advocacy are also worthy pursuits during the back-end process.
An additional “growth” objective at this stage in your sales process is to acquire on-going referrals / advocacy from your customers. Soliciting and even incentivising referrals should be an integrated part of your back-end nurturing process.