When you've written several books, you'll notice something. You'll have one absolute favorite. And it can certainly be different from your most popular one.
One book that works lifts all the others, effortlessly.
If you haven't written a book yet, or you're almost done with your first, this could be it. The book that lifts everything that comes after. Or at least creates the right space for writing that book.
You don't need three bestsellers. But you could very well use a book that does the marketing for all the rest.
Someone reads your book. They want to know what else you've written. The door opens to everything you've made and everything you'll make.
It might be the easiest marketing there is. One book that reaches people.
There are so many factors in play here. The complexity behind something becoming popular barely makes sense. We set things in motion and see what happens. Whether a book lands, sticks, and people buy it isn't up to us anyway.
However, you can do the work that seems useful. What do bestsellers have in common? That question might give you some direction. I share these things here through playful experiments.
If it happens you have more books, instead of focusing on promoting them all, promote your audience's favorite and double down on that. It might carry the others along with it. And if you only have one book or are working on your first, focus on that one before shifting your attention right away to a new book project.
Maybe you don't care about any of this. Popularity simply doesn't matter to you. A few readers is already enough. Maybe your book doesn't even have a goal at all. It just moves how it moves, and you're fine with any outcome.
But if it wouldn't bother you for your book to become (wildly) popular, despite not caring about that, and you don't have to do anything completely different, just do what you're already doing but "smarter", then maybe it's worth taking action on. Phew, that was a ridiculously long sentence.
The work is the same. The care is the same. You're just paying attention to seeming new patterns that already exist.