It's amusing to me, if frustrating, that people seem to believe that bookstores have every book they could ever want in stock.
Not only do we have a tiny, tiny fraction of even currently published books, the odds of a bookstore carrying a specific book besides current bestsellers isn't all that great.
I don't think people fully realize that passing up books in stock at my store with assumption that they can get them later and/or at a cheaper price means they may be missing their best bet. Passing up a book you want to read because you already have too many books is fine as long as you realize that when you finally get around to it, that book may be gone.
I realize that the reader is right now thinking, "Sure, buddy." (I realize that a certain number of you will say that's why you don't buy from bookstores or that you read ebooks, so good on you. I'm talking about when you find a book you want to read and put on your bookshelf right in front of you.)
I can't tell you the number of times that a customer has passed on a book that "they've been looking everywhere for" because it's not a used book or because it's a hardcover (or softcover, as it may be.) I used to straight out tell them, "You're not likely to find that anywhere else..." but have stopped saying that because for some reason the customers see it as a challenge, or worse, as if I'm trying to mislead them.
So here's the truth.
Books are everywhere, but individual titles aren't. Other than current bestsellers or the greatest classics of all time (though most classics can't be found in most bookstores, except as I say, "the greatest,") most books have a certain length of time in the pipeline and then become backlist books, which may or may not stay in the system...usually, not.
The fact of the matter is that lots of books are out-of-print. Those midlist books that are still in print are not carried by most bookstores. If a book isn't being talked about, it fades, and that is 99.999% of the books that have ever came out.
So when I have the odd midlist title in stock and the customer proclaims he wants it but...it's not used or it's not in the right format and they pass, they don't realize that they are missing an opportunity.
Hell, even if another store does has it in stock, just the time, energy, and gas you expend to find it more than makes up the difference in price, but that's an argument for another time.
What I'm talking about is the odds that that midlist book is to be found anywhere else, including used bookstores, and believe it or not, even Amazon.
The most likely way to find an out of print book is through Amazon, to be sure, but even there books aren't always readily available, and even if Amazon is free postage, the actual seller may not be. I've been surprised by how many titles aren't even available on Amazon, or at such outrageous prices that you have to really, really want that book
The second most likely place that will have a title is the publisher, but buying a single book from a single publisher simply isn't feasible.
The third most likely place a title will be found is at Ingram, the last remaining national distributor, but Ingram lets titles slide after their time in the sun.
I'm going to say that the average time in the system in bookstores for even bestsellers is a couple years, with huge sellers, maybe three or four. For the average book, it may be six months or a year. With wholesalers, it may be a little longer than that if there is residual interest, but most books drop out. (Available for reorder, but my experience is those reorders almost never show up.)
So even a good selling book that is more than four or five years old will be gone from most bookstores and even the wholesaler. I see this all the time with Book Clubs who have picked a title that a member loved a few years back. I always check, but more often than not, any book in this time range isn't available anymore. (Should be a rule of Book Clubs that they check availability, right?)
With mass market books, the turnover is even greater. There is a reason that most bookstores these days concentrate on trade paperbacks. Both hardbacks and supermarket paperbacks have a limited shelf-life except for the biggest authors.
Linda and I owned a used bookstore for 15 years and there were a ton of good titles and authors that simple NEVER came in, or would come in once a year and sell instantly. Sure, we had lots of books, but the customer looking for a specific book more often than not couldn't find it, especially if it was an older midlist book. That's why it was so frustrating when they did find one and still passed on it for some reason. The fact was, the bookstore across the street was equally unlikely to have that title.
Good luck with that.
My store specializes in still-in-demand midlist books, which is a niche most bookstores ignore in favor of the current bestsellers. If I find a cult author, I try to carry every book by that author. I try to keep books that have any kind of following in stock. But most bookstores are focused on current sellers, and they send back those that have slowed down.
So yeah, chances of a bookstore having a current bestseller are good, but other than that, the chances for midlist books being in stock are almost random.
You pass on it, and it's probably unlikely you see it again. Of course, if you passed on it after saying "I've been looking everywhere for this," I have to assume that you didn't really care about that title after all.