Definition
Cannibalization refers to the reduction in sales (or revenue) of an existing product, service, or channel caused by the introduction or promotion of a new product, campaign, or channel from the same company.
In other words:
when your new sales come at the expense of your own old sales, not from genuine market growth.
Example 1 – Retail Promotion
- You run a 20% discount campaign on Product A.
- Many loyal customers who would have bought at full price instead buy with the discount.
- Revenue uplift appears high, but in reality, you just shifted full-price sales into discounted sales → cannibalization.
Example 2 – Product Launch
- Apple launches the iPhone 15.
- Sales of the iPhone 15 increase, but some customers would have bought the iPhone 14 anyway.
- iPhone 15 revenue looks strong, but part of it cannibalizes iPhone 14 sales.
Mathematical Treatment
In uplift/ROI analysis, cannibalization is a negative adjustment:
$\text{Net Revenue} = \text{Incremental Revenue} – \text{Treatment Cost} – \text{Cannibalization Loss}$
Where:
- Cannibalization Loss = Revenue lost from existing products due to the treatment.
Why It Matters
- Overestimation Risk: If cannibalization is ignored, campaigns may seem more successful than they are.
- Strategic Planning: Helps decide whether to launch new products or promos, considering total portfolio impact, not just single-product metrics.
- Profitability Focus: True business impact = incremental gain – treatment costs – cannibalization.
Key takeaway:
Cannibalization means stealing from yourself. It’s the hidden downside of promotions or product launches, and must be subtracted from uplift to measure the real net benefit.