You paid for a newsletter mention, a directory listing or a featured slot. A week later, someone asks "was it worth it?" — and the honest answer is often "no idea". UTM tags fix that. They're small labels added to a link that tell your analytics exactly where a visitor came from. They're free, they work with Google Analytics, Plausible, Fathom, Matomo and most other tools, and you can set them up in 15 minutes.
What a UTM-tagged link looks like
A normal link: https://yourshop.com/offer. A tagged link: https://yourshop.com/offer?utm_source=spotlight&utm_medium=sponsored&utm_campaign=october. The part after the question mark is ignored by your website but recorded by your analytics.
- utm_source — who sent the visitor (the site or newsletter name).
- utm_medium — the type of traffic (sponsored, email, social, cpc).
- utm_campaign — your own name for the push ("october", "black-friday").
Good news if you advertise on Spotlight: every outbound click is already tagged with utm_source=spotlight, so you don't need to do anything to see it in your analytics.
Where to find the numbers
- Open your analytics and find the acquisition or sources report (in Google Analytics 4: Reports → Acquisition → Traffic acquisition, then switch the dimension to Session source / medium).
- Filter for your source (for example, spotlight).
- Look at sessions, engagement, and — most importantly — conversions: sign-ups, purchases or contact-form sends.
Was it worth it? The 3-number check
You only need three numbers: what you paid, how many visitors came, and how many of them did the thing you care about.
- Cost per visitor = amount paid ÷ visitors. Useful for comparing channels.
- Conversion rate = conversions ÷ visitors. Tells you whether the audience fits.
- Cost per customer = amount paid ÷ conversions. The number that actually matters. Compare it with what a customer is worth to you.
Example: you paid $120 for a week in a spotlight strip. It brought 300 visitors, 9 signed up, and 3 became paying customers worth $90 each. Cost per customer = $40, value per customer = $90 — a clear win, and a reason to bid again.
Common mistakes
- Judging on clicks alone. Clicks are a means, not a result. A cheap click that never converts is expensive.
- No conversion tracking. If your analytics doesn't know what a sign-up or sale is, set that up first — otherwise every channel looks the same.
- Changing everything at once. If you redesign the landing page during the test, you won't know what caused the result.
- Too short a test. A single day is noise. A full week — like a Spotlight placement — smooths out weekday swings.
Make the most of the visitors you pay for
Send paid traffic to a page that continues the promise of the ad, with one clear next step. Then let the numbers decide: keep the placements whose cost per customer beats your target, and drop the rest. For more on picking channels in the first place, read our small-business advertising playbook.