True CPA 41% higher than last-click reported

True CPA 41% higher than last-click reported

CPA = cost per acquisition.

An edtech brand ran 18 creators, then compared promo-code attribution vs a post-purchase survey. n=18, 60 days.

Last-click code CPA: $22
Survey-adjusted CPA: $31

██████ reported
█████████ actual

Code attribution undercounted because viewers discovered via one creator but bought after seeing another, or searched the brand directly. The gap reframed which creators were actually efficient.

So what: pair codes with surveys; last-click flatters the wrong creators and hides assisted conversions.

Benchmark: creator last-click underreports true CPA by 25–50%.