A partner of ours is sharing a link to one of our events in their newsletter. How can I differentiate the traffic coming from their NL and the traffic coming from ours? for both, I would have source=newsletter and medium=email. What would be a best practice? to differentiate the source (one would be partner-newsletter, the other one own-newsletter) or to add a tag in the content?
Same question for social media, they will share our link on the same sm as us. How do you differentiate between our linkedin post and their linkedin post for example?
There are more parameters in UTM beyond source and medium. I would add in a utm_campaign, or use the utm_content to distinguish sources. That would allow you to determine whether it's being sent from your newsletter or theirs.