ClassPass is an app on which people could book fitness classes.  The app usually give some credits for free for first-time users thus increase their abilities even if they don’t have strong motivations.  Once they use this app and form a regular excercise routine. It will be unlikely for users to cancel the membership, not only because it will break the routine, but also because the cancelling process will need much more physical effort.  By these methods, ClassPass could attact more users without losing them.