Hypothesis: Books that already have high exposure and demand will likely be negatively impacted by making a free version available. Books that would have good s

Hypothesis: Books that already have high exposure and demand will likely be negatively impacted by making a free version available. Books that would have good sales if more people knew about them will likely benefit from the increased exposure from making free versions available. But yeah I personally have had the experience of the first link - I've purchased many physical books that have free (and legal) PDFs online because I like print books better.