May I suggest that if we do this we set time constraints:
A discussion start date, one which allows people who wish to participate enough time to buy, borrow, read or listen to the book and frame their thoughts.
A discussion end date so we can wrap it up and move on to another book.
Allow (say) a month from announcing the book to starting the discussion. This way we can hope to encourage enough people to participate at the same time to get a good exchange of views going. A month allows people who wish to borrow from their library, time for it to be ordered and collected.
The Machine Stops is available in all the usual formats: paper book, audio book, Kindle, drama adaptations. Used copies are available from online retailers from £1. New from £2.70.
In the meantime, pose a few questions and ideas that people can think about as they read. There are plenty of online resources to draw on for this particular book.
Select and announce the next book on the same date the discussion for the current one begins.
A separate thread for each new book. Whoever choses the book “manages” the thread to publicise and keep it active and inclusive until the discussion has started and ended.
How does that sound? Over to you EP.