Totally agree on word-of-mouth promotion. Rob Fitzpatrick writes about getting your book into the hands of 1,000 readers (Tim Grahl's number is 10,000 https://booklaunch.com/book-launch-numbers/). Fitzpatrick's four ways, and I'm quoting:

- Digital book tour via podcasts and online events (most scalable) - Amazon PPC (pay-per-click) advertising (easiest but unscalable) - Event giveaways and bulk sales (fastest if you have the contacts) - Build a small author platform via content marketing and “writing in public” (most reliable and valuable, but time-intensive)

Congratulations on your books!

(You also make a great point on the pain of being ignored or rejected that comes with promotion. Something to consider for a future post—definitely one of the most significant, overlooked, pains imho.)