The new edition includes some additional material, updates, and notes. I don't expect it to fly off the shelves any faster than its predecessor.
This started out as just a sheet of instructions that I gave to coworkers visiting from the States three decades ago. It evolved over time, until I finally formatted it as a book. I put it on my web site. Much more recently, with the advent of easy, no-cost self-publishing, I published it to Amazon as an eBook and paperback, just to improve its availability. The Kindle version only costs a dollar (the lowest price I was allowed to set).
In theory sales should earn royalties for me. But I spent more money registering the copyright than I'm ever likely to earn from sales of the book.