Before Airbnb, there was Saturday: turnover day, weekly rentals, and families reserving next summer's week before this one ended — the Jersey Shore ran on direct bookings for two generations. Today a 60-unit portfolio hands the platforms $200K+ a year, charged identically on first-time guests and families on their tenth consecutive summer. This guide runs the portfolio math, reveals the owner-acquisition angle most managers miss, and lays out the engine — brand searches, AI answers, and a modernized rebooking machine — that gives the invention back.