I recently found this comment below a question:
It sounds like you might want to complete more of your course before taking off on your own. Check out my profile if you'd like a free trial for a training site, they have a few nice courses for people getting started with Unity, and when you're ready, you can take my advanced course :)
This is obviously not an attempt to improve the question or get it answered. It is solely an attempt to get someone to subscribe to a paid service provided by another website. The link in the author's profile seems to include an affiliate-ID which makes me believe that they get some form of incentive for advertising this website.
So I flagged the comment as "other..." and in the free-text description I described it as spam and referenced our "how to not be a spammer" guide.
But to my surprise, the flag was declined and the comment was not deleted.