I know several MoviePass subscribers who do this. Apparently, if you purchase at the theatre with your MoviePass then MP counts the purchase as 'that day', but the ticket kiosk lets you select a future date and MP is none the wiser regarding the details of the purchase. People who pass by a theatre on a regular basis (on the way to work, the gym, etc) can simply collect up a batch of tickets for a future showing and then take a bunch of friends.