LCI

Marketing & Advertising

Loyalty Campaign Incrementality Calculator

Compare treatment and holdout purchase behavior, normalize the holdout to the treated population, estimate incremental revenue and contribution, and calculate cost per incremental purchase.

Treated members-
Holdout members-
Observed treatment purchases-
Observed holdout purchases-
Expected treatment purchases without campaign-
Incremental purchases-
Observed treatment revenue-
Counterfactual treatment revenue-
Incremental revenue-
Incentive, communication, and fixed cost-
Net incremental contribution-
Relative purchase-rate lift-
Cost per incremental purchase-

Decision view

Treatment, holdout, and counterfactual lift laboratory

Treatment, holdout, and counterfactual lift laboratoryPopulation-normalized purchase bars and a revenue bridge separate baseline demand, campaign lift, and the full cost of creating that lift.
Exact scenario comparisonTreatment purchase rate (%) changes while all other entered assumptions remain constant.
Treatment purchase rate (%)Treated membersHoldout membersObserved treatment purchasesObserved holdout purchasesExpected treatment purchases without campaignIncremental purchasesObserved treatment revenueCounterfactual treatment revenueIncremental revenueIncentive, communication, and fixed costNet incremental contributionRelative purchase-rate liftCost per incremental purchase

How to use Loyalty Campaign Incrementality Calculator

  1. Enter eligible members and the actual randomized treatment allocation.
  2. Use mature purchase rates and average purchaser spend from treatment and holdout.
  3. Include rewards paid on all treatment purchases, not only purchases labeled incremental.

Calculator guide

Understanding Loyalty Campaign Incrementality Calculator

Loyalty campaign revenue includes purchases that would have happened anyway. This calculator uses a randomized or defensible holdout to estimate the counterfactual behavior of treated members and isolates incremental purchases, incremental revenue, and net incremental contribution.

Normalize first The holdout rate is scaled to the much larger treated population.
Revenue counterfactual Both purchase frequency and purchaser spend are included.
Full treatment cost Rewards on every treatment purchase are charged to the campaign.

Detailed calculation process

Detailed loyalty treatment, counterfactual, and incrementality calculation

The default campaign assigns 80% of 50,000 eligible members to treatment and retains 20% as a holdout.

General formula: T=N*sH=N-TP_T=T*r_TP_H=H*r_HP_0=T*r_HDeltaP=P_T-P_0R_T=P_T*a_TR_0=P_0*a_HDeltaR=R_T-R_0C=P_T*i+T*m+FK=DeltaR*g-CLift=(r_T-r_H)/r_H The holdout rate and spend are projected onto the treatment population to estimate baseline demand. Only the difference from observed treatment revenue is considered incremental.

What each symbol means

N eligible members (members)
s treatment allocation share (decimal)
r_T treatment purchase rate (decimal)
r_H holdout purchase rate (decimal)
a_T treatment purchaser average spend (currency/purchaser)
a_H holdout purchaser average spend (currency/purchaser)
i incentive cost per treatment purchase (currency/purchase)
m message cost per treated member (currency/member)
F fixed campaign and measurement cost (currency)
g gross margin (decimal)

Worked substitution with the default inputs

1. Normalize treatment and holdout populations T=50,000*0.80=40,000H=10,000P_T=40,000*0.18=7,200P_H=10,000*0.145=1,450 The raw purchase counts are not compared directly because the group sizes differ.
2. Build the treatment counterfactual P_0=40,000*0.145=5,800DeltaP=7,200-5,800=1,400R_T=7,200*$86=$619,200R_0=5,800*$79=$458,200DeltaR=$161,000 The revenue counterfactual preserves both the holdout purchase rate and holdout purchaser spend.
3. Charge the campaign and calculate lift C=7,200*$7+40,000*$0.18+$6,500=$64,100K=$161,000*0.48-$64,100=$13,180Lift=(18%-14.5%)/14.5%=24.14% Positive net contribution does not by itself establish statistical confidence.

The default campaign creates an estimated 1,400 incremental purchases and $13,180 of net incremental contribution, subject to the validity of the holdout.

Worked situations

Practical examples

  • The default treatment contains 40,000 members and 7,200 observed purchases; the holdout implies 5,800 purchases without treatment.
  • Observed treatment revenue exceeds its scaled counterfactual by $161,000, creating $13,180 of net incremental contribution after all campaign costs.

Better inputs

Useful tips

  • Assign the holdout before message exposure and preserve it through the purchase window.
  • Use net merchandise revenue consistently in both groups.
  • Check statistical uncertainty separately before acting on a small modeled lift.

Before relying on the result

Limitations and common mistakes

  • This deterministic calculator does not calculate confidence intervals or correct non-random assignment.
  • Spillover between treatment and holdout can bias the counterfactual.
  • Long-term habit formation, pull-forward, and customer-level margin differences are not modeled.

Reference

Key terms

Counterfactual
The estimated treatment-group outcome had the campaign not occurred.
Incremental purchase
Observed treatment purchases above the population-normalized holdout expectation.
Relative lift
Treatment purchase-rate improvement divided by the holdout rate.

Important note

Do not call the output causal unless treatment assignment and measurement support that claim. Review sample balance and confidence intervals outside this deterministic estimate.

Frequently asked questions

Can I use last year's buyers as the control?

Only with strong caution; seasonality and selection make a contemporaneous randomized holdout preferable.

Why is incremental revenue not simply incremental purchases times treatment spend?

The model also recognizes the difference between treatment and holdout purchaser spend.

Does positive contribution prove significance?

No. Economic value and statistical confidence are separate tests.