You may limit the spots you open to Classpass members but in my opinion, Classpass members are paying customers too and pay a membership fee and should not be treated differently than regular members. I have received an email from your studio in saying that when a Classpass member comes, your studio only gets a portion of the regular rate you charge a client and that is why you would cancel the class even if the client is there if they are a Classpass member. To me that is bad practice because there is a difference in treatment. As a business, you know what you are getting in repayment when you partner with Classpass. And as far as I know, it is a way to attract new clients to sign up with your studio outside of Classpass if they decide to take more than 3 classes a month. Any studio that turns away a client that is already there and waiting is a studio that needs to revisit their policy, period.