Why this concept matters so much
Not every attributed sale is extra revenue. If a customer who would have bought anyway arrives via a voucher code site, you pay commission on revenue you already had.
Incrementality therefore determines the real value of your programme: not what is measured, but what would not have existed otherwise.
Which publishers are often most incremental?
Content partners and comparison sites that introduce your brand to new audiences typically score highly. They create demand that would not otherwise exist.
Parties sitting close to the checkout, such as voucher code sites, are more often partly cannibalistic. That is not necessarily wrong, but you want to know.
How do you test incrementality?
The cleanest method is a holdout test: pause a publisher type in one market and see whether total revenue drops or simply shifts to other channels.
Additionally analyse new versus returning customers per partner and the overlap with your own branded search traffic.
What do you do with the outcome?
Shift commission towards partners who demonstrably bring new customers and tighten terms for partners who mainly harvest existing demand.
DIKKE KASSA reports per market which partners deliver incremental volume, so your commission budget goes where it truly buys growth.