Composit Ticket - Pros and Cons when subscribers exchange frequently

Hello,

Just stumbled upon Composit Ticket's and was wondering what the Pros and Cons are for organizations that allow their patrons to exchange easily? 

When we print and mail the compost ticket at the beginning of our season, and a patron exchanges one show in their package, does the printed composit ticket become invalid?

Any other items you could share about composit ticket environments would be greatly appreciated!

Best,

Stephen