What is True Wasted Spend?

True Wasted Spend is hourly spend above what the conversions in that hour were worth at the account's own average CPA — a stricter measure than simply counting zero-conversion hours.

Why it matters

An hour that produced one conversion but spent five conversions' worth of budget still wasted 80% of its spend. Zero-conversion filters miss this; True Wasted Spend catches partial waste inside "working" hours, which is where dayparting decisions actually live.

How ClickCatalyst detects it

The account's average CPA is computed from its own 30-day history. For every hour-of-day block, spend above (conversions × average CPA) is classified as waste. Only hours with at least 50 clicks are surfaced, so low-volume noise never drives a recommendation.

avg_cpa = SUM(cost) ÷ SUM(conversions)   // 30-day window

true_wasted_spend(hour) =
  GREATEST(0, hourly_spend − hourly_conversions × avg_cpa)

Significance guard: clicks ≥ 50 per hour block

Example

If 2–4 AM spends $120 while producing one conversion at an account average CPA of $40, that block's True Wasted Spend is $80 — a dayparting candidate even though it "converts".