Put a QR code on the wall where you train. Gym-goers spin for a free session or a guest pass and leave their name, email & phone number. Your next client is already in the building.
Build a list of your own, from people who chose to spin.
A free session gets people to try you.
Follow up with everyone who spun, while they still remember you.
You set each prize and its winning percentage, and limit spins per day, week or month.