Slate's got a stupendously good piece up about the business of selling used books on Amazon. Far from the refined, antiquarian hobby you might think it is, the used book salesman of today is involved in a high-speed, hyper-competitive battle to find product. In fact, they even have specialized equipment that allows them to determine if a book should be purchased.

It's not fancy stuff, but it works. In this case, a laser scanner jacked into a Dell PDA loaded with a database of current book prices crushes any smartphone.

The technology angle is incidental to Michael Savitz' main narrative, but it's certainly a part of it. Beyond the (totally awesome) Dell PDA, it is the fact that Amazon forms one huge common market for booksellers that forces even the smallest players to compete at global speed. All the inefficiencies, like say, reading the books, get squeezed out.

My [laser] scanner lies at the end of a cartridge that is fitted into a Dell PDA--a species of technology now obsolete for nearly every purpose but this one. Anyone with a smartphone can scan barcodes on books, but these people aren't the competition, exactly. Smartphone scanner applications, which interpret photographic images of barcodes and then look up the corresponding products on the Web, work too slowly to be tools for the professional. With the PDA and laser scanner, I work at the speed of the retail cashier.

My PDA shows the range of prices that other Amazon sellers are asking for the book in question. Those listings offer me guidance on what price to set when I post the book myself and how much I'm likely to earn when the sale goes through. The scan happens fast and the prices are stored locally, in a database that I download onto the device from a third-party company. If, according to the settings I've plugged in, a book is sufficiently valuable, the program shows me a green "BUY" bar across the top. If it's a dud, I see a red bar: "REJECT."

When I first started this work, I would wake up every morning with fingers stiff from prying apart books in order to get a better look, and a clear shot at the barcode. On average, only one book in 30 will have a resale value that makes it a "BUY." One man's trash is, of course, nearly always another man's trash...

The old-fashionedness of my PDA echoes the marginality of the work I do. I rely on a technological castoff to search through other people's castoff merchandise.

Read the full story at Slate.

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