Having the option to create a recurring package. One of my offerings is a 10 pack of training sessions and I would like to be able to set it up as recurring based off usage. So after the client uses all 10 session of the 10 pack it would automatically renew for 10 more sessions without needing the client to go in and buy 10 more or to approve payment each time. Some of my clients prefer 10 packs instead of the monthly recurring due to travel schedules and what not but I don't want to have to chase them down for approval every single 10 pack since I have it laid out in my agreement that the 10 pack renews after each 10 sessions.