>So I guess I'm saying if you want print books, you should make that known by buying physical copies of books. Cos if the trends I see continues, I can't imagine it'll be practical to do print tech books too far into the future.

Agree with your sentiment but I don't think economics will be the cause of fewer books being printed. The technology for printing has advanced to the point that Amazon and other Print-on-Demand companies are able to fulfill their standard delivery promises for online orders without even carrying inventory.