Sure. That still doesn't answer the question of who does hear about it. We could just say that 1% of people who read SF have heard about it, but then my experience is hard to explain - I hadn't read all that much SF by age 11. It seems quite reasonable to say that the 10 years that the Internet existed between me and Harry was decisive, but I'm asking what variables explain the difference between two SF readers, only one of whom has heard of cryonics.