Glossary · Marketing Strategy

Hidden Cost of Over-Optimization

also: Goodhart's Law · brand erosion from performance

Definition

The hidden cost of over-optimization is Goodhart's Law applied to marketing: when a bidding algorithm targets short-term conversion KPIs exclusively, it systematically degrades brand equity and long-term customer value. The damage is invisible in the optimization metric but visible in downstream retention and organic traffic.

Bidding algorithms optimize the measurable. If conversion value is reported as first-order revenue, the algorithm funnels budget toward low-LTV channels and discount-hunters. Brand searches decline silently; direct traffic decays; organic retention slips. Goodhart's Law: when a measure becomes a target, it ceases to be a good measure. The fix is composite objective functions (conversion times retention times brand-search lift) and periodic re-calibration against held-out experiments.

Essays on this concept