Self help books are the most filler heavy books. They often have a useful point, but they just don't need to be a book much of the time. This is unfortunate for the authors who have often put significant time into producing the information. Technical manuals typically need all of their content due to the level of detail, and novels need all of their content because it's the content which provides enjoyment. For self help, people just want to know what they need to do to make their lives better? Maybe the work has to move into academia where we have existing infrastructure for rewarding non profitable work for the good of the public?