Yes, good point. One of the things I worry about, most, with regard to people who buy (specifically) Nooks, is that they're buying into a bill-of-goods that is not guaranteed. B&N is not promising to ensure that there will always be ready-access to lots of free choices. (To be fair, neither did
Amazon, with regard to the Kindle.) As with
many aspects of emerging technology, a lot of what you see
today is a reflection of getting people hooked on the new technology, and then
later changes will monetize the great value people are getting today, for free. The big question is When is later? and that needs to be considered in the context of how long you expect your Nook (or Kindle) to serve you. I don't know about you, but I'm planning on using my Kindle for at least four years - maybe more. In that time-horizon, is
not rational to expect the same extent of free books that I'm enjoying today. If you're expecting this gravy train to last that long - or even longer, if you think your Nook or Kindle should last you longer than four years - then you're much more likely to be disappointed.