On the other side of the equation, I did spend a few pre-Amazon years calling up bookstores and asking if they had books in stock by ISBN. At least a few clerks were confused by the whole ISBN thing which confirmed my own experience that while working in a bookstore can be great, there's a very good chance you won't be trained in anything relevant. Ah well.
One of the best days of my life was realizing that there are whole forums devoted to finding old, vaguely remembered books, seeing as how my brain literally keeps me up at night remembering old books and fervently wishing I could find and read them again. This is, of course, all for the best because now I don't have to troll bookstore phone lines pestering the employees if they remember the name of a book from the 1980s that was about a boy and there was another boy that looked like him and there was pie. Not that I would be tempted to do that.
This is an Open Thread. Starting topics: working in a bookstore, experiences with bookstores, and books that you can't find or remember. Derail away!