My first "real" job in the book business was as a junior buyer or assistant buyer at the largest book wholesaler. This is an often-overlooked job, but a very cool one. Well, being an assistant or junior isn't very cool, but it leads to being a senior or lead buyer, and that's a cool job.
Buyers are generally assigned to either a single publisher (or publisher group if dealing with small presses) or a genre. Where I worked, the junior buyers were assigned to particular publishers, and the senior buyers were assigned to formats. So I bought Hearst books (now a part of HarperCollins) and I worked with the audio book buyer, the mass market buyer, the trade and hardcover buyer, and the children's buyer. There were two children's buyers and two trade and hardcover buyers. Other companies (such as B&N) buy by genre, so they have a cookbook buyer and a mystery buyer, etc.
As a junior buyer, my primary responsibility was buying Backlist. Different companies have different definitions for when a book become backlist, but it's usually within 3-12 months of its initial publication (in each format - a new paperback isn't automatically backlist because the hardcover was out last year.) I bought for 7 warehouses weekly. You want to find a balance between having enough stock to fill all orders, and not having overstock. It's easy to have tons of overstock and fill all orders, or not have a lot of stock and fill very few orders. But neither of those are what happens when a good buyer is doing their job right.
The computer systems have a lot of data, especially on backlist. It will tell you how many copies of this book your company sold this week last year, the last 4 weeks, the last 4 weeks averaged, year to date, last year, and so on. Hopefully you'll also be able to see demand, as the sales might be artificially low if you ran out of stock. You want to know how many people tried - and failed - to order this book, to see how much more over the average sales to purchase, or else you'll just run right out immediately again. It should also have information on seasonality, so you know to buy more of a Summer Reading book in the spring, and more of diet books in December, to be prepared. The computer will have a recommended quantity, and will want to help you out by placing all the orders automatically, but of course computers are never as smart as they think they are, and I had to go through my orders pretty much line by line to make adjustments. Often the computer overestimates and you can run out of money pretty fast.
What do I mean by run out of money? Didn't I promise in my headline that you were using someone else's money? Well yes, you are, but there isn't a infinite amount of it, just because it isn't yours. You often will be given an "open-to-buy" which is a dollar amount of your budget. One way to improve it is to process a return back to the publisher. Your same computer system in addition to generating recommended buys, will also create recommended returns lists, so you can see if you have a book selling on average 10 copies a week, with 4000 books on hand. Which means you have 400 weeks of books on hand. That's a problem. When I was a buyer, our goal was to have 4 weeks' supply on hand. You might think we'd want 1 week, but with variable shipping times and reprint times, 4 weeks' was much more reliable. If you're a buyer for a major chain bookstore, you'd want to have large quantities of New York Times Bestsellers on hand in all stores to make displays. But everything else you only want 1-2 copies of on hand, as everything else you can get in 1-2 days from the wholesalers. Wholesalers want to have a broader selection of books on hand, as stores tend not to order bestsellers from them (in fact, bestselling authors peak at wholesalers 3-4 books before they peak at retailers) but instead order obscure titles from them.
So the majority of my week was spent in front of a computer, keying orders over and over again for the same books. Boring. But there had to be something to keep me going. New title buying sessions! Seasonally I'd get sets of catalogs from the publishers (mostly electronic these days.) First, I'd send them off to be entered into the system. When that was done, I'd have to go through each one and confirm they were done correctly, as no one knew my publishers as well as I did, and often small (but important!) details weren't correct. Then I'd start doing research on comparison/competitive titles. In addition to the catalogs, I also got pages called Sell Sheets. These should each list 3-4 comparison titles for every cataloged book. However, they usually only list them for the easy books, and list nothing for the hard ones. This is very careless of the publishers as I had to have something for every book, and for the hard ones I might come up with bad comparisons. Basically, if I was looking at a diet cookbook, I'd want to look up the sales of 4-5 other diet cookbooks, preferably a couple from the same publisher as the new title, none more than 3-4 years old, same format, similar price point. And then we'd look at how those other books had been selling, and the senior buyer would determine the New Title Buy based mostly on the sales from those other similar books. And they really need to be similar. You wanted to compare a British mystery to other British mysteries. You want to compare a New York chick lit book to other New York Chick lit books. And the reason for using the same publisher is because some publishers are better at particular genres than others. For instance, Harlequin is never going to be known for their literary fiction, and similarly Knopf is never going to do a good job with romances. So you want to know if Sourcebooks is good at publishing cookbooks, or if Wiley is good at business books. Otherwise you can end up way over- or under-buying the books in question.
Finding the comparison titles, and then the new title buying sessions were definitely my favorite part. Then it was simply the relationship with the sales reps (and their assistants.) Smart, bookish people, they were always fun to talk with. They would send copies of books (pre-publication) that they thought we'd like (or you could request them.) They did ask for a lot of reports but those were pretty easy to run. It was in their best interest to give us accurate information, not to try to force books down our throats. Media is unique in that all our products (books, movies, music) are returnable whereas mostly everything else in a retail store is not. So media sales reps see a direct correlation to their bottom line if they suggested we buy a lot more of a book than we needed, as we'll send them back. But it isn't in a sales rep's best interest to try to force anything down your throat even if it's for nonreturnable products like bookmarks, bookbags, or other sidelines. The simple reason is that if they ever want you to buy something else from them in the future, they'd hate it if you said "Looks like I had to clearance 80% of the last batch of goods I bought from you." It still comes back to bite them. So it's to their advantage to tell you if they think a book is a sleeper, if it's not an author's best work, if the early buzz is great or not great. A buyer and a sales rep should have a cooperative relationship, not an adversarial one. Still, it's fun to be the buyer, as they are the one in the driver's seat in this relationship.
There's always something new. And the buyers know about all the new books first. It was a fun, challenging job. Yes, people are always threatening to replace Buyers with computers, but that will never happen. Readers' tastes are too fickle, unpredictable, and the book business doesn't do nearly enough research about what sells, what doesn't, and why. Without that information, buying systems will remain fancy calculators.