Benjamin Mitchell says that Chris Sells and I have missed the point when we fret. Benjamin says: "The mistake being made here is to think that the value of authors is based around conveying factual knowledge." I can't speak for Chris, but I don't think I'm making that mistake. I grant that lower cognitive level training (including fact knowledge) may not be where the greatest use-value is, but these have traditionally been the areas of the greatest sale-value. Particularly what Benjamin Bloom defined as "Application"-level knowledge has always been the big seller. These verbs associated with Application will be familiar to anyone who receives show catalogs, reads magazine covers, or book backs: "solve," "show," "use," "illustrate," "complete," and "examine."
"Comprehension" and "Application" have been the bread-and-butter of technical training. Internet technologies are becoming much more efficient at distributing information at these cognitive levels. I think that it would be foolish for an author / trainer to think that existing business models / individual careers will not be dramatically altered by that.