I have mixed opinions about this one. Although I’m not a big fan of people leaving a comment clearly in hopes of making my readers into their readers, there is a middle ground. If we’re already on the topic, then I fully understand the link. For example, I wrote a post one (of hundreds) post on dogs. Somehow that started a conversation about cats. Somewhere along the line, I ended up reading cat posts from other readers and linking my own. If it makes sense for the conversation and someone is already leaving a comment, I get it. But if it’s solely a comment meant to redirect readers away from what I wrote, then I see why that doesn’t work.
As far as celebrities, again, mixed opinions. A few celebrities follow me. (I’m always wondering how long it’s going to take for them to unfollow me, but hell, they’re still there.) So if I write something that is relevant to them — specifically if I’ve interviewed them or am talking about their songs — again, it’s logical to do. I can think of one celeb off the top of my head who I wrote an op/ed piece about due to his political/social justice stances. He thanked me and retweeted the post. Shortly after, he followed me and I ended up interviewing him. Sometimes there are professional reasons in which this absolutely makes sense. But again, if it’s just harassing celebrities, not so much.