I was intrigued by what you said about hyperlinking vs. tagging. You mentioned Facebook, Instagram, and LinkedIn.

My understanding of Facebook tagging is that, when you tag someone in your post, the post will appear in all their friends’ feeds. So, yes, that’s a cheap way of hacking into an audience that may be inappropriate or undeserved. If someone gave you significant help with your book and you want to make a single post that is primarily about them to say “thank you for being a great colleague,” or if you want to share a flattering photo of them attending your author reading, it may be appropriate to tag them so their contacts see it. By contrast, if you’re primarily telling people to buy your book, you shouldn’t tag others.

If you just tag someone in a comment under a Facebook post, the tagged person receives a notification, but I don’t believe it privileges the post in their friends’ feeds. I think that’s a way of letting them know you’d like to open a public discussion with them. In some cases, with your actual real-life friends and colleagues, it may be better to draw their attention to your post by private message (or, heavens, a phone call!) rather than a public tag.

I do most of my literary promotion on Twitter, however, where tagging works differently. In my experience, on Twitter, it’s very common to tag someone when you compliment their work, and it’s very common for the complimented person to retweet the nice thing you said about them (assuming they are not already a famous person who receives a hundred compliments a day and are just too busy to read them all.) A tag of my Twitter handle doesn’t leverage my Twitter followers (I don’t think?) unless I choose to retweet it, so I don’t see it as a “hack” of my followers, but rather as an offer of free publicity that I may choose to amplify if I wish. In the Twitter literary community, tagging and retweeting is a win-win for mutual acknowledgment and visibility. I’ve tagged authors in hundreds of quotes/compliments of their work, and no one has ever complained. I generally don’t tag others in mentions of my work; that would be weird.