REGIONAL OVERVIEW
Prime Day 2026: UK
Ad efficiency gains during the event faded within a week
- UK revenue fell 14% year-over-year on 34% less traffic: but shoppers who showed up converted 33% better.
- Ad spend rose 14% YoY and ROAS jumped 74% during the event: with CPC down 27% — a genuinely strong four-day result.
- That efficiency didn't hold: ROAS stayed 32% below baseline for the full week following the event.
Download the full Prime Day category report for UK.

Key takeaways
- UK demand came from a smaller, sharper audience: Revenue fell 14% year-over-year on 34% less traffic, but shoppers who engaged converted 33% better than last Prime Day.
- Event media efficiency improved sharply: Ad spend rose 14% year-over-year while ROAS jumped 74% and CPC fell 27%, a strong four-day result.
- The efficiency gain did not last: ROAS stayed 32% below baseline for the full week after Prime Day, while ad spend remained elevated.
