What is Margin Erosion?

Margin Erosion is losing money on paid sales while ROAS looks healthy — ad spend quietly exceeding the gross profit of the products it sells.

Why it matters

ROAS compares ad spend to revenue, not to profit. A 4x ROAS campaign selling 20%-margin products loses money on every sale, and the algorithm keeps scaling it because it only sees the sale, not the loss.

How ClickCatalyst detects it

True profit is calculated as gross profit (revenue minus cost of goods) minus ad spend — the number the dashboard hides. A revenue-versus-profit waterfall shows exactly where margin disappears, step by step.

Break-even ROAS is derived per category from gross margin: a product with a 30% margin needs at least 3.3x ROAS to break even; anything below loses money per sale. Campaigns are then split into a Kill List (pause — they lose money with every sale) and a Scale List (profitable and proven).

true_profit    = SUM(gross_profit) − SUM(ad_spend)

breakeven_roas = 1 ÷ gross_margin_rate
  e.g. 30% margin → 1 ÷ 0.30 = 3.3x

Example

One audit found a "Basic Cotton T-Shirt" generating −$1,800 net profit after ad costs while contributing positively to campaign ROAS — a textbook margin eater.