I hadn't heard of BookTalk on Tik Tok, having had a look, I think it would absolutely be worth giving it a try. DAMN, that's another skill I will have to learn ;-)
Social media is ongoing. The sooner you start the better. There is an ex cop who promotes his book solely on Twitter. He posts something funny (unrelated to his books) every day and about once a week adds a review or a post about his books. He has done exceedingly well.
I like the look of your three books on Amazon, nicely presented and great reviews. Our issue is, how do we let people know they are there and that they are worth their time and money.
I think it's about getting known, garnering an audience, which you have done here. Although, I find Medium isn't a place for promoting books. For me, Medium has been a fantastic learning curve for my writing and I enjoy learning and writing here. Sometimes it pays, too.
Quora, for me, has been brilliant for getting an audience. When 10,000 people eye an answer there are bound to be some who are curious enough to look you up. A numbers game.
I seriously doubt there are many people who can anonomously write a book and have it become a bestseller without any promotion.
There is only so much time in the day and achieving a balance is important.
Most importantly, enjoy it.
Email: mmcewan@madasafish.com