My former acquisitions editor called today. She works for Pearson in NYC. (Prentice-Hall, Penguin Books, Addison-Wesley, etc.) It was a social call; we worked together for many years and for several publishers and we were getting caught up. Our imprint kept getting acquired, so we were with Henry Holt, IDG Books, Wiley, etc.
Debra told me something revealing. We've discussed this topic before on this board but up until now all we had was opinion and speculation.
She said that more than 50% of the books published now by Pearson are digital rather than print.
That is a significant revelation.