Measuring incremental FTDs from a promo, in 5 steps

Measuring incremental FTDs from a promo, in 5 steps

Run a deposit-match promo and FTDs jump — but how many would've deposited anyway? Without incrementality, you're paying for conversions you already had.

▸ Step 1 — Hold out a control: randomly exclude ~10-15% of eligible players from the promo. This is the only honest baseline.
— Step 2 — Run the promo to the test group over a fixed window, same GEO/source mix as control.
— Step 3 — Compute FTD rate in each group. Incremental lift = test rate minus control rate, not the raw test number.
— Step 4 — Cost it: divide total promo spend by incremental FTDs only. The true cost-per-incremental-FTD is often 2-3x the naive figure.
— Step 5 — Compare that true cost to your CPA on the same GEO. If the promo's incremental cost exceeds CPA, buy traffic instead.

The discipline is the holdout. 'FTDs went up' is not evidence the promo caused them.

Benchmark of the day: across ~12 promo tests with proper holdouts, naive FTD lift overstated true incremental lift by a median of 2.4x.