Why affiliate marketing customer interviews need a participant plan

What to take away

The first mistake is recruiting participants before writing down who qualifies, because that yields answers nobody can compare or act on.
Settle three things before booking callswhat makes someone a customer, which market they buy in, and which decision the findings will change.
Choose a sample size you can justify to finance, then stop once answers start repeating.
Sort consent, storage and deletion before the first call, not afterwards.
Cost the exercise in pounds so it survives the next budget review.

Choose participants before you book the calls

For an affiliate marketing programme, interviewing anyone who clicked an affiliate link yields browsers, not buyers. Define a customer as someone who completed a purchase within a stated window, then record the affiliate route or publisher where the participant can identify it.

Inclusion criteria to write down

Geographywhich countries or regions
Purchase recencywindow for buyers
Route to sitehow they arrived
Spend bandminimum and maximum
Exclude staff and agency contacts
Rule for borderline participants

Write inclusion criteria you can defend

Write criteria down and keep them: geography, purchase recency, route to site and spend band. If the programme sells only in one part of the UK, say so and record where each participant buys.

Add a rule excluding staff and agency contacts, which stops you interviewing yourself. Decide in advance how you will handle participants who fall just outside the band.

Recruit through channels you already own

Publisher newsletters, post-purchase emails and customer panels recruit faster than cold outreach. Under the direct marketing and privacy and electronic communications rules, consent and soft opt-in conditions shape who you may contact and how.

Screen respondents against the criteria before booking a slot. If your sample looks thin, use the affiliate marketing audience research guide to widen it without losing segment detail. Book in batches so note-taking stays consistent.

Ask questions that lead to programme decisions

Every question should point at something you can change: commission rates, creative, publisher mix or onboarding emails. If you are researching journeys on affiliate networks such as Awin or CJ, ask what publisher or content prompted the purchase; do not assume tracking records alone explain motivation. Questions that only satisfy curiosity cost the same to ask. A question you cannot act on is one to cut.

Keep the set short and comparable

Use a fixed order of open questions so answers can be compared across participants. Ask what they saw, what they compared and what they did next. Keep the guide to twelve questions and pilot it once. Test promotional wording too, because claims in ads and offers sit under consumer rights and issues rules on advertising and promotions.

Handle consent and notes properly

Explain what happens to notes, how long you keep them and who reads them. Recording needs its own agreement. Store notes against a participant ID rather than a name wherever you can. Delete recordings on the date you promised. Tell participants how to withdraw and what happens to their data if they do.

Turn answers into something the business pays for

Findings that change nothing get filed and forgotten. Agree who owns each finding before the interviews start, and name the meeting where it will be presented. That owner should read the notes, not only the summary.

Worked example cost in pounds

£400ten interviews at £40 incentive
£150recruitment admin, six hours at £25
£320analysis, eight hours at £40
£870total for finance conversation

Cost the exercise in pounds first

Worked example for a small UK-based retailer: ten interviews at £40 per participant incentive is £400, and recruitment admin, six hours at £25 per hour, adds £150. Analysis, eight hours at £40 per hour, adds £320.

The total, about £870, is the figure a finance conversation needs; these amounts are illustrative. If the work runs across two quarters, split the cost so both budgets carry a share.

Check the findings against your personas

Test each finding against the buyer personas in England you already hold. Use the Jobs to Be Done framework to ask what the customer was trying to accomplish and what influenced their choice. Where evidence and persona disagree, update the persona and note the date. If you want a structured planning method, CIM runs strategy and planning training courses covering research design and prioritisation.

Common questions

How many interviews should one segment have?

There is no fixed number. Some teams stop when themes repeat. Others book eight to twelve and add a round only if findings conflict.

Do I need consent to email past affiliate customers?

For email to individuals, PECR generally requires consent unless the soft opt-in applies; UK GDPR also applies when you process personal data. Check the ICO's direct marketing guidance before contacting past customers, and assess live-call or recorded-call rules separately.

Does the method change outside England?

The core interview method does not change across the UK. PECR and UK GDPR apply UK-wide; record which market each participant buys in, since offers and delivery promises vary.

What if participants contradict the persona?

Keep both records. Note the contradiction, then check whether the persona describes a buyer you no longer target.