[lavalampkid]

Ticketmaster interfaces with a large number of absorbed Ticketing services and inventory that they've acquired over the years. Sure selling tickets shouldn't be hard, but try doing it with the number of legacy systems ticketmaster has to work with... especially considering they have so many. Sure they could rewrite a single system, but they have plenty of teams and applications that interface with specific services that they'd not only have to rebuild the system, but make it compatible with the hundreds of stakeholder's applications (ranging from Sports, Theatre, concerts..).