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Campaign Insights

How AI Reduced CPA by 38%

An anonymised account of a twelve-week optimisation programme: what was automated, what was deliberately left manual, and where the gains actually came from.

Marcus Aldridge22 April 202610 min read

The client is a UK subscription business operating across paid search, paid social and affiliate. Client identity and absolute figures are withheld; all percentages are directional and verified against a holdout.

Roughly a third of the improvement came from model-driven bidding. The remaining two thirds came from creative volume, audience suppression and a landing experience rebuild — none of which were automated.

The transferable lesson is that automation compounds a good structure and accelerates a poor one.

Our position: capability without an operating model produces expensive noise.

Shard & Co · Strategy Practice

This insight forms part of Shard's ongoing research programme. For the underlying methodology or a briefing with the authoring team, contact the practice directly.

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