What each parameter is for
source is where the click came from — newsletter, twitter. medium is the kind of channel — email, cpc, social. campaign is the thing being promoted. Those three are the ones that matter; term and content are for paid keywords and for telling two variants of the same ad apart.
Case sensitivity will split your reports
Email and email are two different mediums as far as Analytics is concerned, and they will appear as two rows for the rest of the campaign’s life. Lower case everywhere, hyphens rather than spaces, and a written convention that everyone follows.
Never put UTM parameters on internal links. They overwrite the original source, so a visitor who arrived from a search and then clicked a tagged internal banner is recorded as having come from the banner — and the traffic that actually brought them disappears from the report.
Frequently asked questions
Which parameters do I actually need?
Source, medium and campaign. Term and content only matter for paid search keywords and for distinguishing ad variants.
Does capitalisation matter?
Yes, and it is the most common way reports get split. Email and email become two separate rows. Use lower case everywhere.
Can I tag links inside my own site?
No. It overwrites the original source, so the channel that genuinely brought the visitor disappears from your reporting.
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