My wife and I recently purchased a family-owned beach home from my parents in their retirement, in Ocean City, NJ. Here, the season runs from about 1 June though 31 August, with only spotty business on the shoulders. The main clientele is suburban Philadelphia, Delaware, New Jersey, and to a lesser extent New York, Virginia, DC, and Western PA. The "culture" here is weekly rentals of the entire house, Saturday to Saturday, where clients bring their own bed and bath linens.
We have a beautiful 3BR, 2 BA, 1250 sq ft house (sleeps 8) about a 3 minutes' walk from the beach.