Please add feature to make booking viral. Inspire with Dropbox that enable to customers recommend the servise by sending a link and both sides get extra storage. There with bookly can be used coupons to generate with an unique links to referral contacts. When one new customer would click on the link (can be saved in cache browser memory) and our current customer would receive also discount on another session by email or sms. I would offer for example 50 CZK coupons and discount on first booking.
This feature will also enable to make current users coming to book our services more often if they get discount from referrals.