WaitlistPing

Calendly has no waitlist. WaitlistPing adds one: connect your Calendly account and get a waitlist link for each event type, to share when you're fully booked. When a booking is cancelled, everyone on that waitlist gets an email with a direct link to the freed time, so the slot gets rebooked instead of wasted. No code, connects through Calendly's secure sign-in. Needs a paid Calendly plan. 14-day free trial with no card, then $15/month.