This document summarizes an interview between Marc Grabowski of Criteo and Nat Poulter of MailOnline about header bidding. It discusses how header bidding works by allowing multiple SSPs to bid simultaneously in a header auction rather than a traditional waterfall. Nearly half of UK publishers have adopted header bidding and Criteo's top publishers have also adopted it, seeing great returns. However, there are still questions around whether the benefits will remain as buyers adapt, and if header bidding will truly become an industry standard or remain a disruption.