Tickets that depend on other tickets

Real events have rules: the after-party ticket only makes sense with a main ticket, the coach seat only if you've bought entry. Rebll's ticket-type engine now models exactly that — a ticket type can be made available only when another one is in the basket, with its own caps and per-order limits.

It turns a pile of separate products into a coherent journey, so promoters can build up-sells and bundles that only appear when they're relevant — and customers never see options that don't apply to them.