And Speaking of My Book:

[I warned you I could be shameless about promoting this book of mine . . .]

Maybe everyone already knows this, but it was news to me: the price that Amazon charges for individual books fluctuates (rather widely) from day-to-day. For instance, (and I assume this is generally the case), I've noticed that my book, which lists for $27.95, has been priced as low as $18.45, and as high as $22.75. That's a pretty big swing, percentage-wise.

There are a couple of interesting things about this. It's a very risky strategy, it seems to me. Having the ability to instantly recalculate the price charged for goods can be very efficient, of course, in allowing a merchant to respond to fluctuating changes in demand and fluctuating price points. On the other hand, it is a strategy that can only work well when it's not widely known that it is taking place. It's the opposite, if you will, of those "price guarantees" that many merchants offer -- consumers hate feeling like they've overpaid for goods (even if the dollar amount is relatively small, nobody likes the feeling of having been "stiffed"), and if they are reassured ex ante that they are protected against that risk they will be more likely to part with their money. Conversely, the knowledge that the price might drop at any moment gives them the incentive to defer their purchase -- perhaps indefinitely.

Have I blown their cover? Or was this in the category of common-knowledge factoids that somehow I had just missed picking up?

[And please note -- I am not unaware of the cruel irony that, if I'm right that this isn't widely known, this posting itself might have the perverse effect of reducing everyone's incentive to buy my book by making it more widely known (and thereby giving all you potential purchasers the incentive to defer your purchase . . .). Probably not the greatest marketing strategy, for me -- but chalk this one up to my naive Jeffersonian belief that, in the final analysis, more information is always better than less. Plus, what's a few bucks among friends?]

Eli Rabett (www):
Eszter Hargittai wrote on this at Crooked Timber.

The bottom line is that Amazon not only sells things directly but is a marketplace with multiple sellers for many things
1.23.2009 8:42am
DS Dan:
Amazon used to guarantee that if their price dropped within 30 days of your order, they would credit you the difference upon request. Alas, this policy is no more.
1.23.2009 8:54am
r.friedman (mail):
Actually, the price doesn't change, just the exchange rate between internet dollars and US dollars.
1.23.2009 8:57am
There is a frozen steak mail order company called Omaha Steaks that sends emails to customers with specials. Depending on buying habits and how long it has been since a customer ordered, the customer is directed to different versions of the web site with entirely different prices.
1.23.2009 9:00am
Some thougts:

If people hold out, won't the price drop to a point where some people will stop holding out (thus establishing a market price for the book)?

Airlines do this, and people bitch, but people still fly.

Ever bought stock?
1.23.2009 9:03am
tired of blogs:
I take advantage of this by storing my wish list in my shopping cart's "save for later" section rather than a wish list. Then, every time I go to the shopping cart and a price has changed, a box appears at the top of my cart to inform me of the change. I can also scroll through the save for later section to look at the proportions on the discounts. Paperback books and trade paperbacks are rarely discounted more than 40%, usually no more than 32%, but hardcovers enter remainder eventually and can hit 60-90% off, and can be as much as 50% when new. And sometimes Amazon's pricing model seems to glitch: I recently noticed that a boxed set of hardcovers with a retail price of over $100, not yet in print, was priced at $35. I put in my pre-order then for the pre-order price guarantee. A few days later, Amazon actually sent out a notice asking me to confirm my order within 48 hours, probably trying to rectify their mistake.

I just wish that the wish list section of the site provided the same notification of price changes, because I'd rather divide books by topic, etc. I tend to keep small academic press stuff in the wish list, since it's rarely discounted, and leave the popular/commercial/Oxford/Cambridge-type stuff in the "save for later" section to benefit from the often enormous (and transient) discounts.
1.23.2009 9:32am
DS Dan:

You're right about that price guarantee, but on a case by case basis, Amazon will cave. For example, over Christmas, I bought a big screen TV. The next morning, the price dropped by $80. I e-mailed Amazon to complain and they promptly (within 90 minutes of me sending them the e-mail) credited me the difference, although they said that the credit was contrary to policy and based on my "extraordinary circumstances." Still, I got the $80.
1.23.2009 9:40am
Would this post have anything to do with the fact that right now it is actually at 18.45? :)
1.23.2009 10:02am
Stuart M. (mail):
I'm just pissed that Amazon has started collecting NY sales tax. That kills off a huge piece of their competitive advantage for me.
1.23.2009 10:08am
Dick King:
Stuart, it's not their fault. Your beef is with the state legislature and governor.

1.23.2009 11:17am
Jim Wilson:
Don't worry, David, you have not "blown their cover." This has been known for quite a while. What's interesting is that it's continuing, given the earlier outcry.
1.23.2009 11:36am
People also like bargain-hunting. I bet the number of people who complain when they realize they've been overcharged is substantially less than the number of people who, like tired of blogs, play their game and enjoy it.
1.23.2009 12:27pm
richard1 (mail):
What I don't understand is the logic behind the price changes. I often buy fairly obscure CDs of vintage r&b/pop music from the Ace label in England. The list price is $21.99 but they are often discounted down to $13.99. I can put a half dozen discs in my shopping cart and during a weeks time, the price will usually go down to $13.99 or $14.99, then go up to $18.99 or $21.99, then drop and go up again almost on a daily basis. Anybody have any idea what marketing strategy is behind this? I could see this for recent big selling release but these are speciality items where the total sale per disc is unlikely to exeed 5,000
1.23.2009 1:21pm
Dick King:
There are rumors that Amazon might offer different users different prices at a given time based on other facts about their history.

I would like to encourage every US customer with an amazon account to shop for this particular book at 6PM Eastern Time and report on the price they get offered.

1.23.2009 1:28pm
David Schwartz (mail):
Surely the hope that you may find a lower price in the future is at least partly balanced out by the fear that you may find a higher price in the future? And when you do find that lower price, part of your normal "do I really need this?" logic may be shorted out by the "I found a deal!" reflex.

And the tension helps Amazon massively. The more times you sign on to check the price, the more hits they get and the more opportunities they have to market other things to you.
1.23.2009 2:14pm
tired of blogs:
David S. -- Assuming a reasonable degree of impulse control, the thing to watch for over time is regularities in Amazon's pricing. As I noted above, commercial trade paperbacks pretty much top out at 35% off or so (until they're remaindered). So if I know I'm going to buy a book, I'll watch it hover between 10% and 25% off until the day it hits 32-35%. Watching the prices constantly, though, also permits you to keep track of the occasional flukes in the pricing model, where something is discounted substantially more than usual. Sure, Amazon gets more chances to sell me stuff, but with a rule of never buying a paperback unless it's at least 30% off, hardcover 40%, etc., I can afford a couple extra books!
1.23.2009 2:36pm
tired of blogs:'s perhaps also worth noting that the shopping cart is the one part of Amazon that doesn't show ads, at least for me, and you can bookmark it directly.
1.23.2009 2:37pm
This post reminded me that I had placed the book in my cart - and it was listed at $18.45 for me today as well. Congrats David - you got at least one purchase out of today's post!
1.23.2009 3:25pm
another David:
You can track the price of an item here:

(The tracking history for this particular book unhelpfully begins today, but other items often can be tracked for a much longer period of time.)
1.23.2009 5:47pm
Bama 1L:
When I want to the grocery store last week, all General Mills cereal was marked down. This week, at the same store, the General Mills stuff was back at full price, but the Kellogg's products were discounted. Also, there were different bottled juices at the ends of the aisles from one week to the next, some marked down and some not. This week it was store-brand at what seemed like a good "4 for $5" price; last week it was BOGO on Welch's.

It's as though retailers were insidiously making minor changes to their displays and prices in order trick customers into thinking they were finding special deals or new products!
1.24.2009 2:32pm
Bama 1L:
P.S. I just went to and bought a different book! You've played into their hands, professor!
1.24.2009 2:36pm
another David:
Often it seems that merchants will reduce prices dramatically just long enough for someone to post a link on FatWallet or SlickDeals, then jack them back up in time to benefit from the increased traffic.

Amazon in particular seems to discount grocery prices on items that have been on its virtual shelves for too long, so buying clearance-priced groceries can get you large packages of products with relatively little time remaining until the expiration ("best by" or even "use by") date.
1.25.2009 11:42am

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