I had to delete a new comment on an older post about local quilt shops. Someone, I'm assuming the owner of the store, left an anonymous comment that was a mini-commercial for their local business. If it had not been anonymous or if it had been phrased differently, as in "Hi, I have a new quilt store in the area. Please visit my business and tell me what you think", I would have reacted differently, but the way the comment was done hit me the wrong way. I'm not here to give you free publicity unless I am commenting about my dealings with you. I'm happy to use your name when I have good things to pass on and want local people to check out your store. But, to be fair, I don't think I've ever criticized a person or a business by name when I was unhappy with their actions; the other party wouldn't be able to give their side of the story. (OK, you might catch me out on that comment if you checked all my posts, but I try not to do that. I've written a lot of words in this blog and don't remember all of them.)
I don't do comment screening and I don't block anonymous comments because I like to read a variety of opinions and until now have not had any bad experiences with advertising, sleaze or spam-like comments. Anonymous comments are ok because I understand some people want to limit their web presence - I was that way for a long time. But I know bloggers that have had to invoke comment moderation to protect themselves and their web persona.
In short -- in my opinion, that advertisement masquerading as a comment was tacky.