Thanks for the clarification, Ali. So help me again with what your concern is, as far as getting incorrect data from your tagged links. If someone reshares your post within Facebook, I would think you’re still good. Anyone clicking the link on their share is still coming from Facebook as a result of your campaign, so no harm, no foul, right?
If you’re concern is someone sharing the post outside of Facebook, I’d question how often that actually happens. It doesn’t seem to me typical behavior. It’s neither easy nor intuitive to share a Facebook post to another network, so I don’t think it happens often enough to be concerned about. Far more typical, I think, would be someone would click the Facebook link, go to the content on your site, and then share it elsewhere from there. At that point, whether the UTM tags get passed to the new share depends on how they share it. If they use the sharing buttons on your page, should be no worry. However, if they copy and paste the URL, or use something like a social sharing browser extension, then the tags would be preserved.
In that case I fall back to my original position: no attribution data is ever perfect, and should never be taken literally. It’s best use if for relative comparisons.

Hey Mark, Thank you for the reply. Now, coming to your question, the UTM code is placed in the body part of the post. Let’s say I have a blog on my website that I have shared on Facebook, so I would add a UTM to its original link so that I have the statistics about the users coming to my website from that specific post. I don’t see the need to add UTM to a button of a paid campaign as Facebook gives the data that how many people have clicked on my button.
By the way, your videos are really great. Keep up the good work.

It certainly can happen that a tagged URL posted to one place can end up in another if users copy and/or share that URL. There really isn’t anything you can do about that, but I think it’s rare enough that it’s not going to throw off your overall relative metrics. I say rarely, because in most cases the user has to do some gymnastics, going outside the normal sharing flow, to make this happen. For example, instead of using a sharing button, copying and pasting the URL into a social post. That happens, but I think it is only a minority of users that would go to the trouble of doing that.
In any case, you should never take any traffic metrics too literally (and you don’t need to). That is, you should never expect that if analytics says 542 people came to your page via “source x” that exactly 542 people hit that page. It doesn’t matter, because the important thing is the relative comparison between metrics. So if source A sent 500 visits (according to analytics) and source B sent 250, the important point is that source A sent roughly twice the traffic as source B. The exact numbers aren’t critical, and the errors and misattributions tend to even themselves out between channels over time.
Now as for your specific example, can you tell me where the tagged link is placed in the Facebook post? Is it in the body of the post? On the CTA button of a boosted paid post? The featured link in an organic post? Where it is makes a difference to how likely the tagged link is to get carried over into a share to another network.

I suggest you read my Marketing Land column https://marketingland.com/google-analytics-social-channel-broken-heres-fix-227330 where I go into much greater detail about the problem and why customizing the Social channel was our best solution. By the way, we do UTM tag all our links, and that’s the crux of the problem. We use a set of custom tags for Medium on many of our links. For example. we tag links use in our paid social media campaigns with the Medium “paid-social.” Our social share buttons (from Social Warfare) automatically add the medium “social-warfare” to links they generate, which also would not be captures by the default Social channel definition.
Since that medium is not recognized by the default Social channel definition, that traffic was being dumped into the (Other) channel. We keep very strict rules on our link tagging, and know precisely what tags are used, so specifying those as custom rules works great for us, and we now have all our social traffic showing in Social.

Let’s break it down:
– You create the links and tag them
My advice would be to use utm_medium standard values like social. It’s more robust than using custom values and changing the default channel definitions. Sooner or later someone on the team will misspell a custom value or come up with a new value which isn’t covered in the channel definitions yet and you have traffic in the Other category again. You can only fix this for future traffic.
Here’s a list of values Google Analytics recognizes: https://support.google.com/analytics/answer/3297892
Note they are case sensitive.
– Someone else creates the link and there’s no utm_medium tag
I don’t think changing the default channel definitions can help you here. If there’s no referrer the traffic will be reported as Direct, if there’s a referrer it becomes Referral or Social.
– Two scenarios where changing the default channel definitions is a good solution:
a) A third party, say a media partner, is using custom values for utm_medium in links to your site and you can’t get them to use standard values.
b) Google Analytics puts traffic from a particular source into the wrong bucket. One example that comes to mind is the search engine duckduckgo.com, which is reported as Referral but should be Organic. I’m sure there are also smaller social media platforms which are reported as Referral.

Except you can only do that for links that you can tag. That won’t cover traffic from any links you didn’t create. When people copy and paste your page’s URL into their social post, or share using a third party tool, your UTM tag is not included. So my solution covers the large amount of social traffic that we saw getting misattributed that came from links over which we had no control.