What UTMs are for
A UTM is a tag on the end of a URL that survives the click and lands in your analytics. When you share a link to your own content — in an email, on social, in an ad — adding utm_source, utm_medium, and utm_campaign tells you exactly which push a visitor came from. Without them, most of that traffic collapses into a vague "direct" or "referral" bucket, and you can't tell your newsletter from your Pinterest.
The three that matter (and the two that don't, usually)
Always set source (where it's posted), medium (the channel type), and campaign (the specific effort). utm_term is mostly for paid keywords, and utm_content is for telling apart two links in the same place — a header versus footer button, say. Keep every value lowercase with hyphens: UTMs are case-sensitive, so Email and email become two separate rows and quietly fracture your data.
Why this matters for affiliates specifically
UTMs and Amazon tracking IDs tag opposite ends of the same journey. UTMs tag your inbound traffic — which channel brought the visitor to your page. Tracking IDs tag your outbound clicks — which page sent them to the merchant. Put them together and you can follow a reader from the source that found them all the way to the click that earns, which is what turns "I got some traffic" into "this newsletter drives my best-converting clicks."
Consistency beats cleverness
The value of UTMs comes almost entirely from using the same names every time. Decide that email is always utm_medium=email (not sometimes e-mail or Email), and stick to it. A messy, inconsistent tagging scheme is worse than none, because it looks like data while lying to you — the same problem measurement mistakes cause everywhere in affiliate analytics.
Frequently asked questions
What is a UTM parameter?
UTMs are tags you add to a URL — utm_source, utm_medium, utm_campaign, and optionally utm_term and utm_content — that tell your analytics where a visitor came from. When someone clicks a tagged link, your analytics records that source, so you can see which of your own promotions drove the visit.
Which UTM parameters do I actually need?
Three are worth always setting: utm_source (where it's posted, e.g. newsletter), utm_medium (the channel type, e.g. email), and utm_campaign (the specific push, e.g. spring-blender-guide). utm_term and utm_content are optional — term is mainly for paid keywords, content for distinguishing two links in the same place (like header vs footer).
How are UTMs different from Amazon tracking IDs?
They tag opposite ends of the journey. UTMs tag your inbound traffic — which of your channels sent a visitor to your page. Amazon tracking IDs tag your outbound clicks — which of your pages sent a click to Amazon. Together they let you follow a visitor from the source that brought them all the way to the click that earns.
Why keep UTM values lowercase?
UTM values are case-sensitive, so Email and email register as two different sources and split your data into separate rows. Sticking to lowercase with hyphens instead of spaces keeps each source, medium, and campaign as a single clean line in your reports.
Does this tool store my URLs?
No. Everything runs entirely in your browser — nothing you type is sent anywhere, logged, or saved. The tool just assembles the tagged URL locally.