My interpretation of this subscription landing page was that I could preview a few pages from the book to see if the writing style worked for me. I wasn't able to figure out how to do so, as the 'AVAILABLE' link next to the linear algebra refresher simply went to a Patreon page full of locked/unavailable posts. This looks like it could be nifty, but the ultra-polished marketing is too focused on paid conversions and doesn't meet the basic necessaries of "Is this content valuable to me?".