What would be the reasons for not using UTM parameters?

Question

_{Note: by UTM parameters I mean any kind of parameters is used to track website traffic. One can have their own set of parameters and I still count them as using. Or they can use a link shortener to hide the long, ugly and awkward tail.}

Occasionally I see a marketing/seeding link that doesn't have UTM parameters, just the bare link. I think some of the reasons are:

• They don't know about UTM parameters. Perhaps they are just a regular writer on their domain and not knowing about any sort of web analytics

• They don't define their success on how impact their websites are on the internet. They have no intention to use the collected data.

• The benefit of having web statistics isn't worth the effort. To have a meaningful report, you have to: setup web analytic software, add the UTM parameters to the URL, analyze the data. These tasks require knowledge, and you have either to spend time to learn it, or spend money to have someone done it for you

• Their main sharing platforms have built-in traffic tracking methods. If they don't run a lots of channels they could just be using a more singular channel pixel or conversions API to provide measurement. If you only have one source of traffic then UTM parameters may be overkill

However, there are cases that I can't assume any reason for not doing so. For example, while the link in this answer is genuine, I presume that:

• The author knows about UTM parameters well
• Their success is defined on how impact their websites are on the internet
• It's likely that they have their own tool to generate the parameters effortlessly
• They have multiple sources of traffic

Thus I find no reason for them to not use UTM parameters. The whole show list on Hacker News is another example.

It's possible that the author's company has some methods of analysis that don't really rely on traffic data, like attribution modeling (MTA) and media mix modeling (MMM). They use probabilistic approach to correlate changes in impressions across channels with changes in revenue. This seems to be only possible for established companies, where they have a dedicated team for expensive and sophisticated data analysis. I understand that this reduces the need of using the parameters, but isn't that the more data the better for them? I don't see why using these models make the benefit become completely futile.

So what would be the reason to not doing so?

_{Follow up question: When does one not need to analyze how their website performs?}

Answer 1

I assume the answer is usually just going to be that most people simply don't need the information they provide. There's really no need to collect data that you have no intention of ever using, and tracking always impacts negatively on the user.

A few negatives:

• They make the URL ugly and it signals to the user that they are being spied on. To some users who don't know what they are, it may even make the link look suspicious.
• URL shorteners create links that are mysterious and even less trustworthy. People like to know where the link will take them. URL shorteners also tend to break over time, so any SEO benefit is lost.
• Data is getting less accurate due to increased public awareness of privacy and browsers like Firefox offering core options to remove it.
• If you are doing dodgy link building, it may signal to Google that the link is a paid advert.
• It doesn't seem a particularly accurate way of getting the data. You have no control over how other people share your link, and they aren't going to protect that string's accuracy for you.
• If the data was really important, there are more accurate ways to get it. Increasingly, this means a server-side approach.