An outdoor brand with one hard selling window and post-iOS in-platform numbers nobody trusted. Spend had to triple across Google Shopping, PMax and Meta prospecting in eight weeks without flying blind on platform-reported ROAS.
Single peak season + post-iOS platform-reported ROAS nobody trusted - triple spend in 8 weeks or miss the window
Blended MER with geo-holdout as the truth source + creator-UGC pipeline + cross-channel budget allocation
Google captures intent, Meta drives cold prospecting - both judged on MER, not platform attribution
Geo-holdout-measured incremental MER climbed from 2.3 to 3.6 across the 11-week peak season - the cross-channel allocation worked because we judged it on the right number.
Year-over-year peak-season revenue lifted 118% on a tripled spend base - efficiency held because the geo-holdout MER let us scale into the right channels.
Despite tripled spend, prospecting CAC dropped 29% - the UGC pipeline outperformed studio creative on cold reach, and the cross-channel layering reduced channel-on-channel cannibalization.