For me it was my old ipaq in 2000 that started me using a device to read. With the ms reader for lit files and a couple of other apps I forget the name of for text and html files I was able to read in bed with no lights on
I used various models of ipaqs until about three years ago and still have a couple of functional ones around collecting dust but find I prefer my samsung 7 inch tablet due to screen size.
I remember when baen started including a rather large number of non related books including the book purchased in various ebook formats when buying a hard cover copy of a new release in 2002.