Yeah, bookstores are great for new books or random finds, but I find that if a book's been out for a few years, they tend to fall into the hole of 'not new enough to stay in the main/chain bookstores, but not old/popular enough for used bookstores'. And libraries don't always have the budgets to buy every single book. Which is why I do like online bookstores - and ebooks - because you can still buy the book you want.