This morning I noticed a low-quality question with a comment written yesterday by the user MathKid containing the text:
you may ask such questions at websites like [other site] and get it answered there.
Given the shady business model of this other site, I was surprised to see it recommended by a member of this site. A glance at the user's activity tab reveals that they made 14 such comments about 23 hours ago. The text is very similar to the 36 comments made by the user Mike Williams in three bursts last year:
MathStack Exchange is not for homework problems. You may ask such questions in websites like [other site] and get quick answers.
I suspect that these two accounts belong to the same person. Whether or not this person is affiliated with that website, their comments on M.SE sound like advertising to me (especially the "quick"). Is this behaviour allowed?