Hong Life CalculatorsUnderstanding the referral program cost calculator — concept and principle
A referral program rewards existing customers for bringing in new ones, often with a reward for both sides. This calculator estimates what each new customer acquired through the program costs you: the two rewards plus a share of the fixed monthly cost of running the program. The result can be compared directly with your customer acquisition cost from ads or other channels.
How it is calculated
- Rewards per customer = reward to referrer + reward to new customer ÷ (purchase rate ÷ 100)
- Overhead per customer = program cost per month ÷ referred buyers per month
- Cost per acquired customer = rewards per customer + overhead per customer
The calculator assumes the referrer is rewarded only when the friend buys, while the new-customer reward goes to every referred sign-up. Since only part of the sign-ups buy, each buyer carries the welcome rewards of the sign-ups who did not. The calculator shows USD by default but works with any currency.
The principle
Referral costs have a variable part and a fixed part. Rewards are variable: each buyer triggers a referrer reward, each sign-up a welcome reward. Software, design and management are fixed monthly costs. Spreading the fixed cost over the buyers it produced gives a fully loaded cost per customer, the figure you need for a fair comparison with paid channels.
Worked example
- Inputs: referrer reward $20, new customer reward $20, 60% of sign-ups buy, program cost $300 per month, 80 referred buyers per month.
- Rewards per customer: 20 + 20 ÷ 0.60 = 20 + 33.33 = $53.33.
- Overhead per customer: 300 ÷ 80 = $3.75.
- Cost per acquired customer: 53.33 + 3.75 = $57.08.
How to read the result
Compare the cost with the gross profit a new customer brings over their lifetime. If lifetime gross profit is well above $57.08, the program pays for itself. Fixed overhead per customer falls as the program grows, so a program that looks expensive at 20 buyers a month can look cheap at 200. Referred customers often come with an existing relationship to the referrer, which many businesses find improves retention, but measure this in your own data before assuming it.
Common mistakes
- Leaving the purchase rate below 100% when your program pays the new-customer reward only after a purchase; in that case enter 100%.
- Counting buyers who would have joined anyway as program results.
- Leaving out the cost of fraud checks and self-referrals.
Frequently asked questions
Is a referral program cheaper than paid ads?
Sometimes, but not always. Compare this fully loaded cost with your paid customer acquisition cost for the same kind of customer.
Should rewards be cash or store credit?
Store credit usually costs you less than its face value because it is redeemed against your own margin, and some of it is never used.
Why does a lower purchase rate raise the cost?
The welcome reward is paid per sign-up, so fewer buyers share it. At 50% instead of 60%, the cost per customer rises from $57.08 to $63.75.
Sources: P. Kotler and K. L. Keller, Marketing Management, Pearson