Got this question: "What's the best way to market & promote a book?”
Start with writing a book that:
1) Your ideal people will read / use, and
2) Recommend to others
Simple, not easy. But 100% where you need to go.
Take the time and steps to write the right book for the right audience. Slow is smooth (getting the “book” dialled in to your readers), and smooth is fast (so more people recommend it).
True for books, SaaS products, just about anything. Even the success of (honest) sales & marketing systems are based on happy customers who are willing to recommend your stuff.
As AI blows up all the infinite forms of paid and organic marketing (and spamming and scamming), there will be even more incentive for people to stick to word of mouth as sources of stuff they want to buy and use.