I received How to Write Adventure Modules that Don't Suck today from an Amazon-affiliated store.
The item's description on the seller's page and the waybill say it's paperback. But what I got is definitely hardback - and lovely it is too.

I was wondering if the seller made a mistake and sent me the wrong format - in which case I have to notify them of their error - or whether this book was only ever available in hardback.
I did a bit of research and discovered that the book was originally produced as part of a Kickstarter project. It seems that the idea was to produce a softback, but upgrade to a hardback if the project received sufficient backing which it seems to have done.
Were both soft- and hardback editions produced or was the book only ever printed in hardback?
Apologies if I posted the above in the wrong forum.