Reply To: PassBookBack to Forum
One of the biggest advantages, was originally the fact that passes/tickets/vouchers on passbook would be available offline. In the early days of travel apps, you could not access your boarding passes offline. This has of course changed, with airlines like BA making boarding passes available offline within their own apps, but this is not the case with all airlines (yet).
Outside the airline industry, you can store tickets and vouchers that you would otherwise have to log in to your accounts to access or have to have hard copies of, such as ticketmaster tickets etc.