Then again, most of my buyers are bargain buyers. In remainders and bargain, a best seller is a very different and more interesting animal, not effected so much by popular delusions and the madness of crowds (a little bargain reference*).
The daily best seller page is one of the most viewed pages on this blog. Each day I post the title that sold the most on the previous day and, while some make sense in a New York Times sort of way, most are interesting just because they are so far off the usual top ten. Many are probably not in the top million.
I don't think it generates more sales, though I think it does get some people to request my lists. One day it's an advanced test prep title, the next it's Curious George, the next it's a history of the oil industry. What my daily bestseller list does do, or at least I hope it does, is help to show how diverse and healthy this market is, how bargain is a part of a successful business plan, no matter what area of the industry you're in.
All of my best sellers are sold by me to my customers, which is to say, mostly bookstores. They don't necessarily reflect what my customer's customers are buying at the moment, only what my customers have confidence will sell in the not-too-long run. So, while there is the occasional Mitch Albom or Nora Roberts (Eric Carle, Hannah Arendt, James Joyce... Matthew Quick), most come from my customers' best market niches, whether or not my customers or I previously knew about those niches.
This is not to say my best sellers are not the product of my customers' businesses. I sell to a number of larger customers whose buys definitely skew the numbers their way. More interesting to me are the best sellers for the days those larger customers are not buying.
And the list reflects other aspects of my business. Many of my customers rely heavily on children's and young adult for their bargain sales. A few of my customers order much more frequently and in greater quantities than others. Some customers only order a few titles in heavy quantities a few times per year. Some days I have many orders, many titles per order, some as many as 1000 titles, but all in small quantities: 2s, 3s, 5s. On those days the best seller might sell as few as 25 copies. Some days I get very few orders, with a few titles per order, in high quantities per title.
Full disclosure: Most (about 80%) of my daily bestsellers are generated when one customer buys one title, and the quantity ordered is just, or much, higher than any other quantity ordered, combined or otherwise, of any other title that day.
One of the keys, if not the key, to best sellers in bargain is that you, the buyer, build them. They often don't happen all at once the way frontlist or even backlist best sellers do. You generally know what those are when you first buy them, before you see the numbers. Not necessarily so with bargain.
You will probably know which books are going to be good, solid sellers. These are usually from hurts sorters (see glossary page here) and are in your back list stock or your used bookstore has customers asking for them regularly.
Bargain best sellers, on the other hand, frequently will surprise you. A bargain priced book is often not the same book as it was at full price. You merchandise it differently, your customers see it differently. The book may have simply been overpriced by the publisher to start with, or aimed at the wrong market. Now it might become an impulse buy near the register, whereas it was previously shelved in the wrong section. A front- or backlist young adult nonfiction book about addiction and recovery, shelved spine-out in the young adult section, priced at $16.95, is not going to sell anywhere near as well as the same book, stacked near checkout, priced at $5.95.
The building begins as you get to know what your bargain bestsellers are. First you buy a few copies and, when they sell out quickly, you buy a bit heavier. You might have started with 5 and then bought 10. When that 10 sells out quickly again, you buy 20. They sell out even faster and you buy 50. By now you might have discovered why they are selling so well. The author, previously unknown to you, is local, or the subject has relevance to your community that you were not aware of. Maybe a teacher at a local community college is surprisingly popular and recommends this book to all students. Or it might just be that pictures of kittens and monkeys hanging out together in strange places while playing musical instruments with their.... oh never mind. There is no predicting some of these. Just rock and roll with them, make your customers happy.
The fear, especially if you have a small store without a lot of traffic, is that you will get stuck with your last buy. Just as you receive the last shipment, your customers lose interest and you are making a new desk out of the cartons of books. In fact you can almost always make that last buy sell. It was your bargain best seller; you just need to push a little harder to make the last buy sell out. If you have seasonal sidewalk sales, it will sell then, or at an expo sale, or just during the holidays.
More often than not, the supplier sells out long before you run into an overstock situation, and you end up thinking you should have bought heavier on your second-to-last buy. Then you start building the next best seller.
* Extraordinary Popular Delusions and the Madness of Crowds, by Charles Mackay, first published in 1841, was a huge best seller as a bargain reprint in the 1980s, and probably would be again for many years to come if, say, Wordsworth Classics would bring it back (oh wait, they did! Order some now, this book sells).