Hire your first marketer once you have some signal about which channel and message actually work — not before, since a marketer hired to figure out the whole strategy from zero is an expensive way to run your first round of experiments. At that stage, the right profile is usually a generalist operator who can run experiments across channels and get their hands dirty, not a narrow specialist (paid-only, SEO-only) or a senior strategist with no execution muscle.
Many early-stage companies get more mileage from a fractional CMO at this stage — enough strategic judgment to set direction, without the cost or ramp-up time of a full-time senior hire before the playbook is proven.