Every book that I have purchased that wasn't because of my own review has been a rec from either an author or another reader on Bluesky since joining. Literally all of them. And I'd say posts from authors themselves have been 75% of those purchases. So keep posting about your books readers are
I am not first and will be far from the last to say this: I have purchased so many books because I saw them recommended or publicized here on bsky. I cannot urge you all enough to KEEP TALKING ABOUT BOOKS. I know it's easier to talk up someone else's book, but this also means you, the shy author.