I know I’m late to this, and technically the discussion is closed, but might the book’s popularity have something to do with people’s increase in consciousness about the environment, climate change, etc? Kya lives so close to nature, and in such a different way to most of us (no TV or telephone, let alone the internet), that her experience itself is novelty. At a time when increasing numbers of people are choosing not to fly and to eat mostly locally grown food, it might be that readers want to vicariously experience what it would be like to live that close to nature. I’m not sure! It’s late here and my mind is wandering. I looked up the author’s website earlier though and, on it, she talks about wanting to explore (through her fiction) how our evolutionary past affects our present day behavior.