Referral (aka referral traffic) is any visit that lands on your site after a user clicked a link on another website. The external site is the referrer; its domain becomes the traffic Source, and the channel is typically classified as referral (the Medium). This bucket excludes other distinct channels such as Organic Search, paid ads, email, and most social platforms (often tracked separately as Social).
Why analysts care: referrals signal the real-world pathways users take—partner links, PR mentions, review sites, product listings, developer docs, community forums. Strong referral traffic is a proxy for distribution, reputation, and ecosystem fit.
How it’s measured (in practice)
Analytics tools read the browser’s document.referrer (the previous page’s URL). On the first hit of a Session, the referrer’s domain is recorded as the source; the visit is then grouped under the referral channel unless UTM parameters intentionally override it (e.g., utm_medium=referral or something else like utm_medium=partner). If there’s no referrer (bookmarks, typed URL, some app contexts), the visit is usually classified as Direct.
Common pitfalls
- Self-referrals: your own domain or subdomains appearing as referrals—often a sign of broken cross-domain/session stitching.
- Lost referrers: HTTPS→HTTP hops, certain redirects/shorteners, some mobile apps and messenger apps may strip referrers.
- Misclassification: UTMs win; sloppy tagging can push what should be “referral” into “campaign” or vice versa.
- Attribution nuance: referral assists may be undervalued in last-click models—see Attribution Model and Multi-Channel Funnel.
Quick math + mini example
Share of referrals (%) = (Referral Sessions / Total Sessions) × 100
Example: 1,200 referral sessions out of 10,000 total ⇒ 12%.
| Top referral sources | Sessions | Conversions | CVR |
|---|---|---|---|
| docs.partner.com | 450 | 36 | 8.0% |
| reviewsite.io | 300 | 12 | 4.0% |
| community.dev | 200 | 18 | 9.0% |
Analyst notes
- Use UTMs to lock intent (e.g.,
utm_source=partner_site,utm_medium=referral,utm_campaign=integration_v2). - Audit redirect chains and app landings; fix self-referrals and cross-domain flows.
- Inspect Landing Page performance per referrer to prioritize integrations and co-marketing.