Marketing should never be turned off.
This is why, often, a marketing person, not an additional service delivery person, is your first hire. Whether this marketing team member builds relationships with referral partners, builds and maintains marketing systems, facilitates the transition from “I’m interested” prospects to paying customers, or some combination – getting someone whose primary focus is on keeping a steady flow of new prospective customers flowing into your business is the only thing that will get you off the overworked/starving roller coaster that so many solopreneurs are trapped on.
But while you are always marketing – remember the best customers and referral sources are those who have already bought. They leave because of perceived neglect far more often than the others that Dan mentions.