The never-ending cycle is supposed to work like this: Customers lead to an endless stream of purchases and referrals, which lead to another endless stream of even more purchases and referrals from their referrals.
Be careful that you don’t overlook something very important. It will end abruptly if you leave one ingredient out of your sales process: follow up. Yes, that after-the-sale stuff that shallow and short-sighted salespeople resist.