Probably their usual supplier is slower. I haven't had a bookstore order something for me in a few years, but it used to take more than 2 days to get the item.

Probably their usual supplier is slower. I haven't had a bookstore order something for me in a few years, but it used to take more than 2 days to get the item. I'm guessing that the distributors that supply bookstores are optimized to deliver large shipments, not one-off orders.