It went through a minor vogue in our shop a couple years back.
I think there was some worthwhile thought in the process, but if pamphlets sold for $50 nobody would have fluffed it up into a book. Worthwhile thoughts really are nice, and really don’t create revolutions.
Maybe there are conference room minicourses that actually will revolutionize human productivity, but I think if one came along, word would travel pretty fast.