Every few weeks, a thread on the front page gets dominated by meta discussion about how the author is breaking the self-promo guideline. I propose discouraging this by stating in the guidelines that such comments are off-topic.
If people want to help enforce the guideline, I think it would be better to kindly PM the author the first time, and flag as spam if you think they are knowingly disregarding it.
When it’s a public comment, it often overwhelms the original topic. Sometimes it leads to lots of disagreement (not just by the author), which suggests the need for more actual meta discussions like this one, or clearer guidelines. Often it’s upvoted more than anything else, perhaps encouraging others that policing this guideline is rewarding.
People probably check out the author’s submissions before upvoting, but it’s not easy to tell how much someone is self-promoting by looking at their profile. You have to comb through lots of comments — there are members in good standing who author all their submissions, but have many comments on other submissions. As a result I don’t think the public opinion (upvote count) ends up being as fair as it should be.
I can provide recent examples if it helps, but I’m not trying to focus on specific users or comments.