Oh yeah. We get plenty of undisclosed affiliation spam. Sometimes we get R/A content (gibberish and whatnot) from somewhat established users.
Sometimes we even get high-rep users overwhelmingly self-promoting.
Not long ago we had an >10k user consistently posting their project. This is after they had gotten done serving a 3 day suspension for promotional content.
@Yatin Yes, sometimes, it's done by legit or, at least, semi-legit users. In general, one's username is considered an acceptable method of self-promotion.
SE chat's @ notification sound makes me jump every time. Sounds like a large tight spring is being hit on a surface or something. SO's @ notification is much better :)
@Yatin Then, you can change it. [Note: I suggest the version which is on GitHub and linked from an answer. Disclaimer: I've contributed the the version on GitHub.].
@Mast Not .... everything, but I do routinely encounter things about how sites work which I don't like. I prefer "I didn't like that", rather than "I don't like that". Given that I've spent a lot of time on SO/SE, there are quite a few things for which my personal dislike of how it works is largely in the past tense. :)
@Spevacus Yes, I use a large number of his scripts for moderators. I wouldn't use them if I'd identified them as not useful (i.e. yes, I find them useful). I've gone through the list of scripts in his repository and tried nearly all of the ones with a description I found interesting. There were very few which I decided not to use after trying them.
OTOH, I also modified all, or at least nearly all, of them, primarily to tightening up which pages they run on and to eliminate eslint errors, but some functional changes. I still need to submit PRs with those changes.