What system are you using to get the money? The service is taking 25% of your earnings! Also, I believe you could do some optimization with the heavy images. Anyway, thanks for sharing this. It's gonna help my cousin.

Glad the book can help! Regarding image size, it’s on my todo list now (see thread further down the page).

I am using Payhip for the transaction, and then Paypal. Fees end up averaging 0,5€. Calculating in terms of percentage is not really helpful here at such low prices: there is an incompressible flat rate pretty much anywhere you go. See it differently: these intermediary fees go towards making the UX smooth, the payment secure, reducing fraud etc. I want to spend my energy on the content, not making a credit card form :-)