Here are some book marketing sums to depress you.
Only 3% of visitors to a webpage take any action.
For every hundred visitors to your book page on your website, Amazon, Apple, where ever, only three visitors buy the book. Maybe.
With an average of $0.27 per click on Facebook Ads those 100 clicks to sell three books cost you $27 and earned you $6 in royalties.
That’s a $4.50 loss on every book sold.
Virality is key. You want positive comments of your book to be circulated rapidly and widely for free from one Internet user to another.
Maybe put a picture of a pratfalling cat on the cover?