A campaign you cannot measure is a campaign you cannot improve. Yet tracking is the part students understand least: too technical, too abstract. This guide makes it concrete, step by step.
Why tracking is essential
Ad platforms display their own figures (impressions, clicks). But to know whether those clicks produced sign-ups or sales, you must connect the ad to behavior on the website. Three tools add up:
- UTM parameters, which say where a visit came from;
- the pixel, which records actions taken on the site;
- the conversions API, which sends those actions straight from the server to the platform.
UTM parameters
A UTM parameter is a small piece of text added to the end of a link. It lets analytics tools (like Google Analytics) know which campaign brought a visitor.
There are five:
| Parameter | Indicates | Example |
|---|---|---|
| utm_source | The platform | facebook, tiktok, newsletter |
| utm_medium | The type of traffic | paid-social, email, cpc |
| utm_campaign | The campaign name | autumn-launch |
| utm_content | The creative or variant | video-a, image-b |
| utm_term | The keyword (mostly for search) | marketing-course |
A complete link looks like this:
https://example.com/offer?utm_source=facebook&utm_medium=paid-social&utm_campaign=autumn-launch&utm_content=video-a
Best practices
- All lowercase: analytics distinguish “Facebook” from “facebook,” which scatters your data.
- No spaces or accents: use hyphens.
- A shared naming convention for the whole team, written in a shared sheet.
- Never put UTMs on internal links within the site: it would overwrite the visitor’s true origin.
- Use the platforms’ dynamic parameters to insert the campaign or ad name automatically rather than typing it by hand (each platform offers its own variables in the ad’s URL settings).
The pixel
The pixel is a small piece of code installed on a website. It tells the platform about every action taken by a visitor who came from an ad. It is used to:
- measure conversions;
- optimize delivery toward people likely to convert;
- build audiences for retargeting.
For set-up, see Create a pixel and its counterpart Create a TikTok pixel.
Events
The pixel sends events: page view, product view, add to cart, checkout start, purchase, sign-up. Each event can carry information: value, currency, product.
Choice principle: the event you optimize for must be frequent enough to feed learning, and close enough to the result you want. A purchase is the best signal, but if it is rare, an intermediate event (add to cart) can help at the start. See Set up conversion events and TikTok conversion events and attribution.
The conversions API
The pixel runs in the visitor’s browser. But ad blockers, cookie restrictions and some browsers prevent part of the signals from arriving. The Conversions API sends events straight from the website’s server to the platform, which complements the pixel and limits measurement loss. The two are combined, with a deduplication rule so the same action is not counted twice. See Create an API token (Conversions API).
Consent and privacy
In Europe, installing a pixel and collecting data are regulated: the visitor must generally give consent (cookie banner) before tracking activates. Figures can therefore be lower than reality: some visitors refuse. This is not a flaw of advertising; it is a limit to know and to mention in a report.
Attribution
Attribution determines which ad gets credit for a conversion. Platforms use an attribution window by default: for example, a conversion occurring within a set time after a click or a view is credited to the ad. Consequences:
- platform figures and analytics tool figures almost never match;
- a person may have seen several ads before buying;
- changing the window changes the figures, not reality.
The lesson: compare sources and accept a reasonable gap rather than looking for a single number.
Naming campaigns cleanly
A good campaign name reads itself three months later. Example convention:
2026-10_meta_sales_sneaker-launch_cold
| Element | Content |
|---|---|
| 2026-10 | Launch month |
| meta | Platform |
| sales | Objective |
| sneaker-launch | Offer |
| cold | Audience type |
This discipline saves a great deal of time in reports. See Structure a campaign.
Reading results in reports
Once tracking is in place, cross three levels: the platform (impressions, clicks, cost), the analytics tool (behavior on the site) and business results (sales, sign-ups). Formulas are in Digital advertising formulas. Platforms’ custom reports help group these figures; see TikTok custom reports.
Frequently asked questions
What is a UTM parameter for? It tells the analytics tool which campaign, platform and creative brought a visitor.
Do I need a pixel to advertise? It is not mandatory for delivery, but without a pixel you measure and optimize far less well, especially for sales.
Why do figures differ between the platform and Google Analytics? Attribution windows, cookie consent, definitions and processing delays are not the same.
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