UTM links for online stores: tagging campaigns and sales sources

1. Learn the parameters and their roles.

A tagged link looks like this: yourstore.com/shoes?utm_source=newsletter&utm_medium=email&utm_campaign=autumn_sale_2026. The part after the question mark doesn't change the page the customer sees. It only passes a description of the visit to your analytics tool. Parameters are joined with the & sign.

Google recommends using at least three parameters in every tagged link: utm_source, utm_medium and utm_campaign. Missing fields show up in reports as "(not set)". utm_content is useful when one email or ad contains several links to the same page, and utm_term is mainly used for keywords in search campaigns. Parameter values are case-sensitive: to Google Analytics, "Newsletter" and "newsletter" are two different sources.

2. Write down a naming dictionary before your first campaign.

The most common problem with UTMs isn't missing tags, but several names for the same channel. One person types "facebook", another "fb", a third "Facebook". The report ends up with three rows, and sales from one channel get spread across them. So before your first campaign, prepare a short sheet with the allowed source and medium values and share it with everyone who creates links: your agency, the person running the newsletter and your partners.

Choose mediums so that the tool recognizes the channel. Google Analytics 4 assigns traffic to default channels according to rules: the medium "email" goes to the Email channel, "affiliate" to Affiliates, and a medium starting with "paid" or containing "cp", combined with a source from the list of social networks, to Paid Social. A made-up medium, e.g. "newsletter" instead of "email", may not match any rule and land in the Unassigned group. For channels outside these rules, such as creator collaborations, you can create a custom channel group in GA4.

3. Tag only links that lead to the store from outside.

UTMs describe an entry from outside the store. Don't add them to banners on the home page, menu links or buttons in the cart. A customer who came from an ad and clicked a tagged internal banner may be recorded as if they came from a "campaign" on your own site, and the real source of the visit disappears from the report. Use click events to measure internal banners.

Check your paid campaigns too. Google Ads and Meta can append their own click IDs to links, e.g. gclid or fbclid. Don't remove them when editing the URL. If you add manual UTMs to ads, use the same dictionary as in your other channels, so the same campaign doesn't appear in reports under two names.

4. Check the link before publishing.

Open the finished link in a private browser window and check the URL once the page loads. Redirects, e.g. from http to https, from the non-www version or from a link shortener, sometimes drop parameters. If the utm_ part is no longer in the URL after you land, the visit won't be recorded the way you planned. Also make sure the landing page exists and shows the offer the campaign promotes.

Keep links in a single sheet: date, channel, full URL, person responsible. This makes it easier to read the report later and fix a mistake mid-campaign. After publishing, look at the live traffic or sources report and check whether the new campaign appears under the planned name. It's better to fix a link after the first hour than after a week.

• The parameters are visible in the URL after all redirects.
• The values are lowercase and match the dictionary.
• The link doesn't lead to an error page or an empty category.
• The campaign appears in the report under the planned name.

5. Read sources together with sales.

A tagged link describes a visit, not an order. To see sales next to a source, the tool has to connect the purchase with an earlier visit. Some orders will always be left without a source: the customer may have switched devices or come back after longer than the attribution window, and in some tools consent to tracking matters as well. Such orders should be shown separately, not added to direct traffic.

In Flowpeek, the source of a visit is recognized from the link parameters and the referring page, and sessions with no evidence of acquisition are counted separately as unassigned. If the share of direct or unassigned traffic grows after a campaign launches, start by checking the links before you judge the channel itself. How sales are assigned to sources depends on the attribution model, so when comparing campaigns, write down which model you're using.