UTM source and referrer analysis
Understand how Smart Links reports UTM sources and referrers, and why they are not always the same.
This article explains the difference between Top UTM Sources and Top Referrers in Smart Link analytics so you can interpret channel performance more accurately.
Why these two widgets are different
UTM source and referrer are related, but they are not the same thing:
| Signal | What it represents |
|---|---|
UTM source | The source value passed through the Smart Link tracking setup or URL |
Referrer | The website or source that sent the user when a referrer header is available |
Because they describe traffic in different ways, it is normal for them to tell slightly different stories.
In Smart Link analytics, the Top UTM Sources and Top Referrers lists appear in the same view as the other widgets once data is available for the selected range.
What Top UTM Sources shows
Top UTM Sources highlights the source values that traveled with the Smart Link traffic.
This is useful when:
- you intentionally configured source values on the main Smart Link
- variants use their own campaign or placement-level UTM values
- you want a clean attribution taxonomy across print, email, social, and partner traffic
Examples of source values:
newsletterinstagramwindow-posterpartner-event
What Top Referrers shows
Top Referrers reports where the traffic appeared to come from when that information is available from the browser or app context.
Typical examples:
- a website
- a partner page
- a newsletter platform's tracked redirect
- a social platform webview
Why UTM source and referrer may not match
This is expected in several situations:
- a Smart Link was tagged with
utm_source=newsletter, but the referrer shows the email platform domain - a QR scan carries a variant-specific source such as
window-poster, but has no website referrer at all - a privacy feature, camera app, or in-app browser suppresses or changes the referrer
That is why many teams treat UTM source as the planned attribution layer and referrer as the observed traffic context.
How to use both together
The best analysis usually comes from reading both widgets side by side:
| Question | Start with |
|---|---|
| Which planned channel or placement performed best? | Top UTM Sources |
| Which website, platform, or referral context sent traffic? | Top Referrers |
| Why did one placement spike? | Compare both with Scans Over Time |
| Which physical asset drove traffic? | Combine with Scans by Variant |
A practical example
Suppose one Smart Link is used in three places:
- a printed poster
- a newsletter
- an Instagram bio
You might configure:
utm_source=posteron one variantutm_source=newsletteron anotherutm_source=instagramon a third
Later, Top UTM Sources helps compare the planned channels, while Top Referrers may show that Instagram and newsletter traffic came through specific web contexts, and the poster traffic had little or no referrer data at all.