As I see it, the book club's format of requiring you to have read the book in question before you can enjoy the episode runs opposite to it's goal of getting people who don't read books regularly to give reading books a try.
While it would take some form of poll to determine if people are actually going out of their way to read books beforehand, I suspect that most people just listen to the first half of the episode and turn off when Rym says "Before you continue, go read this whole book.".
The reason for me suspecting as such is that, most of the things I have tried due to them being recommended on Geeknights, have been things I later came across and Geeknights' recommendation is what made me choose the item over another.
Another related reason is that, when I'm casting around for something to enjoy, I'll often go through Geeknights episode categories and listen to whatever takes my fancy and I skip over the final thoughts episodes, as I assume most people do.
In short: Making books approachable for people who've rejected books most of their lives as being something that requires a lot of effort to appreciate begins with imprinting as much of a positive expectation of the entertainment contained within. Final thought's episodes should be kept for things most people have experienced.
I propose that, for the book club following The Lies of Loch Lamora, you do the book reviews as a standard review show and ask people to email in or put poll on the website to ask if they felt more or less compelled than with a normal final thoughts style book club.