A 10% discount can look harmless on its own.
So can free shipping.
So can a referral reward.
The problem starts when multiple incentives hit the same order.
Think in total incentive cost
For a promotional order, calculate the combined variable incentive:
product discount + shipping subsidy + referral reward + affiliate commission + gift cost + other variable promotion cost
Then compare the total with contribution margin.
Example
Suppose:
AOV = ₹2,500
Contribution before incentives = ₹900
Discount = ₹250
Shipping subsidy = ₹100
Referral reward = ₹150
Remaining contribution = ₹400
The order can still be attractive if it is genuinely incremental and the customer has strong future value.
It becomes dangerous when the customer would have purchased without the incentives.
Why stacking is hard to manage
The more promotion types a store operates, the harder it becomes to understand the final economics.
A merchant may have:
- a site-wide campaign
- an influencer code
- a referral offer
- free shipping
- product-specific promotions
Each team may own a different promotion.
The customer sees one final price.
That final price is what matters.
Create a promotion hierarchy
Document:
- Which offers can combine?
- Which offers are mutually exclusive?
- Which offer takes priority?
- Which products are excluded?
- Which customers are eligible?
- Which channels are allowed to distribute the offer?
This turns promotion management into a system instead of a collection of codes.
Test the edges
Test:
- one eligible promotion
- two eligible promotions
- excluded product
- mixed cart
- first-order customer
- returning customer
- high-value cart
- low-value cart
The exact combination behaviour should be verified against the store's current Shopify configuration.
Audit real orders
Configuration is not enough.
After launch, inspect orders with unusually high discount value.
Look at:
- discount codes
- discount amounts
- products
- customer
- referral/affiliate attribution
- shipping subsidy
- order contribution
Referbro's Discount Leakage Detector can help identify patterns in exported Shopify order data.
The objective is not to eliminate promotions.
It is to understand the final economics of every promotion combination.