I'm currently running a kickstarter for my LaTeX book. I was thinking that I might change my display name to something like "Don Hosek—author of The Preppy Lion: An Author's Guide to LaTeX" but I don't want to be gauche either, so if there's any objection, I won't do it.
You could add your book name with cover and description to your profile text and also add a link.
You could even use your kickstarter campaign URL as your homepage link.
You could write a blog post on https://tex-talk.net (formerly it was https://tex.blogoverflow.com as TeX.SE blog). I could build and host a book website for you, similar https://latex-cookbook.net including on-page-compiling of sample codes. (I was too lazy to add that book to my profile, but did it for my first book.)
I'd be glad to help in supporting and promoting like above. In my opinion, advertisement in a user name may not be a good choice. A bad sample name to get a feeling: "Jonny—author of Buy Bitcoin" as author of some hundreds of answers or chat messages. Sorry for that :-) it's Jonny not you. And your book is on-topic. Book promotion and kickstarter promotion is good, user names are user names.
Also Twitter announcements of start or progress may be good, such as this one that I made right now: