I can't tell you how many times I thought, "I'll go to store X and see if they have item a. But maybe they don't, I should probably go to store Y because they also have b, c, d, and e. I don't mind paying a bit extra for availability." Granted, I don't do it as much with online shopping, because I know how to online shop. My mom, however. If she doesn't find it in a store she goes to amazon because she knows Amazon has everything. Needs a gardening tool they don't have at the hardware store? Skip the hardware store's website, go straight to Amazon. I'd argue having uranium ore and obscure books does matter to the customer.I would argue that the availability of uranium ore and obscure books matters only when a person wishes to purchase uranium ore and obscure books; the rest of the time they're buying on price and convenience.