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Amazon’s $23,698,655.93 book about flies

michaeleisen.org

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Re: Amazon’s $23,698,655.93 book about flies

#31

Post by AretNCarlsen »

keeran wrote: post #7

I'm surprised the author (and no-one here) hasn't worked out the starting date of the automated price war based on the original RRP of the title :)

bordeebook was effectively increasing their price by a factor of 1.2684/day, and as of Apr 8 priced the new book at $2,198,177.95. I'll guess that the used price ($35.54) implies that the initial pricing of the new book was about $50.

Log base 1.2684 of the ratio of the Apr 8 price to the estimated original price = log($2198177.95/$50)/log(1.2684) = 45 [days]. Ergo looks like the two algorithms started competing around Tuesday, Feb 22.

I'm sure my original price is off, but that actually won't make much difference. If it was $40, then the initial date was Feb 21; if $60, then Feb 23.

[EDIT] By the way, if the price was originally 99c you would still see the $2.2M price after just another two weeks (61 days total). Ah, exponents.

Re: Amazon’s $23,698,655.93 book about flies

#32

Post by lotusleaf1987 »

siegler wrote: post #21

A similar thing happened to me as a seller. I saw that one of my old textbooks was selling for a nice price, so I listed it along with two other used copies. I priced it $1 cheaper than the lowest price offered, but within an hour both sellers had changed their prices to $.01 and $.02 cheaper than mine. I reduced it two times more by $1, and each time they beat my price by a cent or two. So what I did was reduce my p…

Why go to that effort? Did you really save any money, or more importantly time/effort? Paying for the shipping on the other books alone would seem to negate any higher profit margin that resulted in not having to compete with their prices.

Re: Amazon’s $23,698,655.93 book about flies

#33

Post by pwim »

lsc wrote: post #14

oh man. reminds me of the days when I sold books on amazon and half.com. I wrote a script that took the 'nickel less than the other guy' approach. These things are /wonderful/ when it comes to making the market more efficient. Really, though, the shipping costs eat up most of the efficiency. Amazon needs an easy way to say "I want these 10 books, used. Find me the lowest price (including shipping)" - the idea is that…

Nice example of the Knapsack Problem: http://en.wikipedia.org/wiki/Knapsack_problem

Re: Amazon’s $23,698,655.93 book about flies

#34

Post by caf »

ambiguity wrote: post #29
weaksauce wrote: post #28

Earlier quoted context omitted.

I love that. It's a great lesson to programmers that we should think about the extreme cases and have set lower and upper bounds on our algorithms. Sanity checks should be in your code for most applications and inputs.

Amazon should put an upper bound on the maximum price a product can be. Can credit card companies even process a transaction in the tens of millions of dollars?

I remember hearing about someone buying a multi-million dollar artwork with their platinum amex once, so it would seem so.

Re: Amazon’s $23,698,655.93 book about flies

#37

Post by ChuckMcM »

siegler wrote: post #21

A similar thing happened to me as a seller. I saw that one of my old textbooks was selling for a nice price, so I listed it along with two other used copies. I priced it $1 cheaper than the lowest price offered, but within an hour both sellers had changed their prices to $.01 and $.02 cheaper than mine. I reduced it two times more by $1, and each time they beat my price by a cent or two. So what I did was reduce my p…

If you play World of Warcraft this is a solid Auction House technique. I find it humorous to see it applied to the 'real' world (not that WoW economics aren't just as 'real').

The ability to push the price down gives informed actors some pricing control on the market, and the subtext is that it allows for folks to push around pricing to understand the elasticity for any product. Now if you can get them to buy a 'put' of your product :-)

Re: Amazon’s $23,698,655.93 book about flies

#38

Post by jrockway »

JonnieCache wrote: post #25
joshu wrote: post #24

Earlier quoted context omitted.

You think it doesn't?

Well there was the 'flash crash' but it wasn't that big a deal. This financially uninformed hacker thinks it could get much worse some day soon. http://en.wikipedia.org/wiki/2010_Flash_Crash

It won't, because although computers have a lot of control over the market, people also look at it pretty regularly. The reason why nobody noticed a $23,000,000 book on Amazon is because out-of-print biology books are not very liquid. If that were Microsoft stock, someone would have manually made a bet on it, and then the price would have corrected after a while.

Re: Amazon’s $23,698,655.93 book about flies

#40

Post by jacobolus »

lotusleaf1987 wrote: post #32
siegler wrote: post #21

A similar thing happened to me as a seller. I saw that one of my old textbooks was selling for a nice price, so I listed it along with two other used copies. I priced it $1 cheaper than the lowest price offered, but within an hour both sellers had changed their prices to $.01 and $.02 cheaper than mine. I reduced it two times more by $1, and each time they beat my price by a cent or two. So what I did was reduce my p…

Why go to that effort? Did you really save any money, or more importantly time/effort? Paying for the shipping on the other books alone would seem to negate any higher profit margin that resulted in not having to compete with their prices.

Probably because hacking systems like this just to see how they work is inherently fascinating.
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