I’m running a Freeboksy ad and my free book for kids got 800 downloads to date. Yet, only 1 person bought the second book yet. Of course a few days is way too short to see an uptick, even I realize this

But it’s a short illustrated book for kids, after all, takes 20 minutes to read aloud.
In your experience, what’s the reasonable expectation for folks to buy the second book?
As always, I start blaming myself and have that urge to re-write urgently... before I do that, would love to hear about your experience and get some valuable perspective.