> Not sure I follow this. Pre-ordering books is a pretty well established practice among publishers ...
The difference is the person pre-ordering can back out, and generally speaking in pre-orders, no payment is made until delivery. It ends up being a measure of public enthusiasm, not a way to gather revenues in advance of delivery. In this case, people are paying for a book that doesn't exist yet.
> Actually, it's the primary hack for getting on best-seller lists
Yes, true, but see the pre-order discussion above -- generally, no money changes hands until the book is actually available.
Also, I have to add, the ultimate best-seller-list hack is to buy copies of your own book and put the copies back into the pipeline, endlessly, as the Scientologists are said to do.
> Or is this a more basic "No one should sell anything that doesn't already exist" argument?
But that's true in general -- in the worst cases, where delivery doesn't happen, the seller can be charged with fraud. I hasten to add I am not comparing this hypothetical (but all too common) outcome with the book under discussion, which for all I know is perfectly worthwhile.