Pros and cons of tracking referral trafic with "utm" tags

Question

We have a blog discussing products of a variety of manufacturers. Recently a manufacturer asked us if we could utm tag links from our blog to his site with the tags utm_source=OurSiteName&utm_medium=site&utm_campaign=OurSiteName.

Since the manufacturers can already see our traffic in his referral traffic report, I do not see the point of adding utm tags to all our outbound links to manufacturers but perhaps I am missing an important point.

Is there an advantage of tagging outbound links with utm tags instead of just leaving the traffic to appear in the referral traffic section of the receiving website (eg is the referrer information in HTTP requests less reliable than utm tagging,...)?

Answer 1

These tags will show up in Google Analytics so the manufacturer is probably using that for their analytics, rather than something that looks at referral logs. As for how reliable referer (sic) is see this: https://stackoverflow.com/questions/6023941/how-reliable-is-http-referer.

Answer 2

I use this type of tracking with my site, so I find it very useful.

The biggest con I have with utm parameters on the landing page is that it makes the URL very ugly. Users like a site better when the URL is simple, straightforward, and memorable.

When all that information is in the URL, users that copy and paste the URL also get all the parameters along with it. That can throw off your tracking when somebody links into your site organically but has campaign tracking parameters on the URL they link to.

I wish that Google Analytics would redirect to remove the tracking parameters from the URL after it recorded the information in the user session.