The news: Amazon will bring inventory from Roku to its demand-side platform (DSP), the two announced at Cannes Lions, starting in Q4 2025. The partnership will include channels available via Roku and Fire TV devices—giving advertisers access to inventory covering 80% of US connected TV (CTV) households.

The companies said early tests allowed advertisers to reach 40% more viewers at no additional cost and reduced repeat ad placements by 30%. The partnership uses a “custom identity resolution service,” per Deadline, which allows Amazon’s DSP to recognize logged-in users on Roku.

Prime Video ad costs: As advertisers cut budgets and tariffs stifle growth in previously hot sectors like CTV, Amazon is trying to keep CTV an affordable, performance-driven channel—including by doubling the ad loads on Prime Video.