You will be able to read a tagged link and say what each parameter tells your analytics.
Farah sells modest workwear online from a small studio in Geylang. Last month she sent a newsletter about a new range of work trousers, posted the same news on Instagram, and handed out cards with a QR code at a weekend bazaar. Sales went up that week. When she opened GA4 to see which of the three worked, most of the extra visits sat under one label: direct. As far as the report was concerned, those people had typed her address from memory.
They had not. They came from her email, her Instagram bio and her QR code. GA4 simply had no way to tell, because nothing in the link said where it had been shared. This lesson explains the small labels that fix that.
UTM parameters are short labels you add to the end of a link. When someone clicks the link, the labels travel with them to your website, and GA4 reads them and files the visit accordingly. The visitor sees a slightly longer address in the browser bar and nothing else changes.
Here is a link from Farah's next newsletter:
https://www.example.com/trousers?utm_source=newsletter&utm_medium=email&utm_campaign=2026-11-work-trousers
Everything after the question mark is a label. The page is the same page whether the labels are there or not. What changes is the line GA4 writes in its records about where this visit came from.
Three parameters do most of the work, and you should use them on every tagged link.
utm_source names the place the click came from: newsletter, instagram, facebook, bazaar-card. Think of it as the specific site, list or object.
utm_medium names the type of channel: email, social, cpc for paid search, qr. This is the broad bucket, and as lesson 2.2 explains, GA4 uses it to sort visits into its standard channel groups.
utm_campaign names the push the link belongs to, such as the November work trousers launch. It lets you see all traffic for one campaign together, across every source.
Two more are optional. utm_content tells apart different links within the same campaign and source, for example the image link and the button link in one email, or two versions of an ad. utm_term was made for paid search keywords and is mostly filled in by ad platforms now. GA4 recognises a few further parameters as well, but these five cover what a small business needs.
When Farah reads the traffic acquisition report next month, the newsletter visits will appear with source "newsletter" and medium "email", and she can filter by the campaign name to see the whole launch at once.
GA4 works out where a visit came from in two main ways: from tags in the link, and from the referrer, which is the address of the page the visitor was on when they clicked. A click from a Google search or from another website usually carries a referrer, so GA4 can name the source without help.
Many clicks carry no referrer at all. Links opened from email apps, from WhatsApp messages, from some social apps and from PDFs often arrive with nothing attached. A QR code scanned with a phone camera arrives with nothing attached either. GA4 has no information, so it files the visit as direct.
That is why direct traffic in many small business accounts is far bigger than the number of people who really type the address. It is a mix of genuine typed visits, bookmarks, and every untagged click from an app. For Farah, a WhatsApp forward of her product link by one happy customer to a group of colleagues shows up the same way as someone who knew her web address by heart. If that matters to a decision, the link has to carry a tag.
Some platforms add tracking to links for you. Google Ads has a setting called auto-tagging, which adds an identifier to each ad click so GA4 can link the visit to the right campaign, ad group and keyword, provided the two accounts are linked. If you use Google Ads, check that auto-tagging is on rather than adding manual tags on top.
Most other places need you to do it. Meta and TikTok ads let you add parameters in the ad setup, but you have to fill them in yourself. Emails, Instagram bio links, posts, WhatsApp messages, QR codes, partner websites, printed flyers and podcast show notes all need manual tags. Some email tools offer to add tags automatically; if yours does, check which values it uses, so they match the rules you will write in lesson 2.2.
A good habit is to assume every link you share outside an ad platform will arrive as direct unless you tag it, because most of them will.
Tags only label the click. They do not follow someone who sees your post, remembers your shop and searches for it two days later; that visit arrives as organic search. They do not tell you who the person is. And they cannot rescue a visit if the person declines analytics cookies and GA4 does not record them at all. Module 5 returns to these blind spots.
Within those limits, tags are the cheapest fix in this course. They cost nothing and take seconds per link. Before you set any rules, take stock of where you are now: look back at a few links you shared in the last month and work out how each of those clicks would have looked to GA4.
Find three links you shared recently in an email, post or ad and write down how each would appear in analytics without UTM tags.
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