This is going to be psychologically difficult for users to stomach, I suspect. I'm surprised they didn't instead say they'd just take the first $99 of sales - that would put off far fewer people and unless the average book fails to sell more than a handful of copies, it shouldn't take much longer to collect the revenue.
"After the author royalties, PayPal fees and chargeback costs, our gross margin on the storefront is about 8%..."<p>I'm surprised they accept Paypal at all, given that Paypal offers no seller protection for anything but tangible goods via tracked shipping.