If you're reading this article, it's probably because you've found that the Channels report in your Google Analytics account includes an unknown type of traffic called (Other):

You may also have found that some of your Campaign traffic - i.e. traffic from email campaigns or social media advertising campaigns which you've tagged with UTM parameters - seems to be missing from the Channels report.
If so, I've got good news for you - this is a common problem with a very simple fix!
To find out more about why Campaign traffic sometimes appears as (Other) in Google Analytics, and to learn how to stop it happening, have a look at this short video I've made:
If you've found this video helpful, please use the box at the bottom of the page to leave a comment and let me know.