Citi's acquisition of Kard collapses the distance between issuer loyalty infrastructure and merchant-funded rewards economics, pulling a capability in-house that most large issuers have historically sourced through third-party platforms like Dosh or Cardlytics. For issuer processors and network partners, this signals accelerating vertical integration at the top of the card stack — where interchange-dependent loyalty models are being rebuilt around direct merchant relationships to defend margin as interchange pressure mounts.