GA4 has two channel rules that fire on the word shop in a campaign name, and a store's campaigns are full of it. Organic Shopping matches a campaign name where shop starts a word or follows the letter e, or where shopping appears anywhere. Paid Shopping matches the same names when the medium is paid. Google's table checks Paid Shopping before Paid Social, and Organic Shopping before Organic Social and Email, and a channel group files traffic under the first rule it matches. So an email tagged utm_campaign=shop-the-sale can report as Organic Shopping, and a Meta ad tagged utm_campaign=summer-shop as Paid Shopping. Words like workshop or bookshop don't trigger it, but eshop and coffeeshop do. Names like spring-launch avoid the problem.
Never use shopify as the source. Google's source list files shopify and shopify.com as shopping sites. Tag a link utm_source=shopify with a medium of email, social or cpc and GA4 counts the visit as shopping traffic. Name the place the link was posted instead.
Where Shopify shows your tags. On an order, View conversion details and then View full sessions lists each visit with its session referral and, when the link was tagged, a UTM parameters section. Some orders get a shorter summary or none. Shopify leaves it empty when cookies were blocked and nothing was captured, when the order started as a draft order, or when it came from a channel other than the Online Store or Hydrogen, and tagging doesn't change that. In its marketing reports, Shopify says the referrer name can show as N/A when a shortened URL was used as the link, which is one more reason to tag.
Campaigns match exact values. Shopify's example auto-match rule is utm_campaign=elle with utm_source=facebook: a session carrying both joins the campaign, and extra parameters such as utm_content are ignored. A rule only matches what's written, and GA4 treats Meta and meta as two values too, so build every link from one lowercase spelling. For one link per creator, the bulk UTM builder keeps the spellings identical. Shopify also warns that editing a shareable link after people use it changes the campaign report.
Tag all three. Shopify's own help example, ?utm_source=emailcampaign, sets only a source. Google says to always set source, medium and campaign, and a missing one shows as (not set). For Meta ads to your store, start from the Facebook ads UTM builder.