Affiliates bring sales on commission, but share credit with paid ads and can cannibalise campaigns, especially when they step in at the end of the journey (coupons, comparison sites, reward programmes). Setting clear rules avoids attribution wars and duplicated costs.
The essentials in a definition
Affiliate platforms and PPC can work together or compete: affiliates who bid on your brand or keywords may cannibalise sales you would have made anyway. It pays to define rules for bidding, attribution and commissions, measure with conversion measurement and events, and require transparency in partnerships, per the Unfair Commercial Practices Directive.
The typical conflict
The customer sees an ad, searches for a coupon, clicks on an affiliate site and buys. The affiliate gets a commission for the last click, and the ad loses attribution, or both claim the sale. In some cases affiliates bid on the brand name, diverting traffic that would have been direct.
The company may end up paying twice for the same sale.
Setting rules
Establish in the contract what affiliates may and may not do: bid on the brand name, use the logo, publish coupons, use browser extensions. Define attribution windows and which channel receives credit in each situation. Record everything.
Distinguish affiliates who add value (content, comparisons, recommendations) from those who merely capture the end of the journey.
Avoiding wars between affiliates and ads
- Define rules and attribution windows
- Distinguish affiliates that add value
- Measure incrementality and total cost
- Coordinate teams and review the list
Measuring incrementality
Analyse what share of affiliate sales is genuinely new. Compare periods with and without specific affiliates, or with and without coupons. Check the weight of coupon affiliates. Assess the total cost per new customer, including commissions and ads.
Use controlled tests where possible.
Paying twice for the same sale is the cost of having no rules.
Coordinating with ads
Share data and rules between the affiliate team and the ads team. Avoid overlap on brand terms. Align promotions. Review the affiliate list regularly and remove those who harm the brand or add no value.
Track complaints and compliance with advertising rules.
Decision table
| Rule | Example | Effect |
|---|---|---|
| Brand bidding | Prohibit affiliates from bidding on your brand | Avoids cannibalisation and duplicated costs |
| Attribution | Define who receives commission in each case | Avoids attribution wars |
| Transparency | Clearly identify the commercial relationship | Compliance and trust |
| Quality | Assess incremental sales and returns | Avoids paying for sales you would have had |
Common mistakes to avoid
- Paying commission on brand sales. The customer was already on the way; check the path.
- No written rules. Affiliates go to the limit of what is allowed.
- Measuring only attributed sales. Assess incremental effect with tests.
How to measure the result
Compare sales and margin with and without affiliates in tests, the proportion of new customers per affiliate and commissions per incremental sale.
Limits and exceptions
Attribution between affiliates and PPC is complex and disputable, and affiliates’ incentives are not always aligned with yours. Programmes require continuous monitoring and clear agreements. Rules and affiliate networks change. Review terms, audit sales and keep the ability to terminate with those who do not comply.
Illustrative example
Illustrative example: a shop finds part of affiliate commissions are paid on sales from customers who searched for the brand. It changes rules: prohibits brand bidding, pays commission only for new customers and tests incrementality by excluding some affiliates. Total channel cost falls and margin rises, keeping sales.
Frequently asked questions
Can affiliates bid on my brand?
Only if the contract allows it. Set clear rules.
How do I know if they add sales?
With tests and comparison between periods and groups.
Should I cut coupon affiliates?
Assess incrementality. Some merely capture sales that were going to happen anyway.
How do I avoid cannibalisation?
With brand-bidding rules, clear attribution and incrementality tests.
Must affiliates identify themselves?
Yes; commercial partnerships must be clear to consumers, under advertising rules.
For PPC and affiliates to cooperate, define bidding and attribution rules, pay for incremental sales and require transparency in partnerships.
Sources and recommended reading
- Unfair Commercial Practices Directive (2005/29/EC)
- Analytics Help: GA4 recommended events
- Google Ads Help: conversion measurement
Last editorial review: October 2026. Informational content; always confirm current conditions in the official sources before deciding.