I have a data point which supports the thesis, at least in the torso and tail. I have a published two books within the last 16 months. For the first one, publ

I have a data point which supports the thesis, at least in the torso and tail. I have a published two books within the last 16 months. For the first one, published in early 2012, the Kindle sales were usually 2x to 3x that of the print sales. This held steady until around November of last year, and then suddenly declined. Today print sales are nearly 2x that of the Kindle sales. The important data point is that the Amazon sales ranks of both have remained steady.