What is Affiliate?
In web analytics, affiliate refers to a partner (publisher, influencer, coupon site, comparison engine) who promotes your offer and earns a commission for a resulting Conversion. Practically, “affiliate” is a traffic and revenue relationship that you track alongside other Campaign sources.
How affiliate tracking works
- Links & parameters. Partners use tagged URLs, typically with UTM parameters, to identify the affiliate as the traffic Source.
- Sessions & cookies. When a user clicks, analytics creates a Session and stores identifiers in a Cookie (ideally a First-Party Cookie).
- Attribution. When a purchase or Goal fires as an Event, credit is assigned per your Attribution rules (e.g., First Touch vs Last Touch or a custom Attribution Model).
- Privacy. Make sure consent and data sharing comply with GDPR.
This flow is similar whether you use GA4 or alternatives like Matomo, Plausible, or Simple Analytics; the core is consistent: tagged links → session identifiers → conversion event → attribution.
Key metrics to monitor
- Clicks & CTR (from partner placements) → quality of traffic.
- Affiliate Conversion Rate (affiliate conversions ÷ affiliate sessions) — a specialized slice of Conversion Rate.
- EPC / eCPA (earnings per click / effective CPA) — unit economics per partner.
- AOV & LTV. Understand order value and downstream LTV to price commissions.
- Refund/chargeback rate — protects margin.
- Program ROI — revenue from affiliate-attributed orders vs cost (commissions + fees) → ROI.
Implementation tips
- Consistent tagging. Standardize your UTMs across all affiliates; treat each partner as a distinct Source or channel.
- Referrals vs referrers. Network or partner may appear as Referral traffic while the browser Referrer shows the click origin—both are useful diagnostics.
- Event design. Define a clean conversion Event (and any Custom Events) that fires once, post-payment.
- Tracking resilience. Prefer first-party storage, server-side redirects, and deduping across devices/networks.
- Tooling. Whether GA4, Matomo, Plausible, Simple Analytics, or Power BI exports, ensure your pipeline preserves affiliate IDs through to revenue.