The concept is pretty simple: Click on a town, company name or university and you can see what books, CDs and videos are selling particularly well there. The idea, according to spokesman Paul Capelli, is to give Amazon.com users a way to find out what people they may have something in common with are purchasing.
"It helps you find and discover things that you want to buy," he said.
As a few minutes of perusing the purchase circles makes clear, the feature is also good for something a bit less digital: snooping around to see what the neighbors are reading.
In Philadelphia, for example, the book on top of the "uniquely popular" list is Joshua and the City, the fourth installment in a modern-day version of Jesus' life by former priest Joseph F. Girzone. The No. 2 book is former Inquirer reporter Buzz Bissinger's fly-on-the-wall look at Mayor Rendell's first term, A Prayer for the City.
You can, apparently, expect your favorite mall stores to hit the World Wide Web in the future: The top seller in King of Prussia is Customers.com: How to Create a Profitable Business Strategy for the Internet and Beyond, technology consultant Patricia Seybold's study of e-commerce.
"It's chatty, it's attractive, it makes you feel like part of a group," said Carol Kaufman-Scarborough, a marketing professor at Rutgers University-Camden who studies consumer behavior. "You can say, 'Well, gosh, I'd like to be like the people at Harvard Business School, so, gosh, let me go see what they're looking at.' "
For consumers, the purchase circles give some clues about books they might want to read. For Amazon.com, they are another way to draw people into the site and maybe make a sale, Kaufman-Scarborough said.
PART OF THE 'IN GROUP'
"That is a common attribute of different groups we belong to, to want to be part of the 'in group,' " she said. "What you read lately is one of those kind of indicators of being in with the in group."
Amazon.com said its system was designed so results would not be thrown out of whack by just a handful of purchases. For a town to be included on the site, at least 200 residents must have bought something online. To produce the lists, computer algorithms calculate sales volume, then cross-reference it with uniqueness by examining the extent to which a book is selling better in one place than in any other, Capelli said.
The site also tracks purchases by companies and universities. That information is based on what e-mail address users register with. Someone using a "temple.edu" address, for example, would be counted in the Temple University statistics. For the towns, Amazon.com uses mailing addresses, Capelli said.
PROTECTING BUYERS' PRIVACY
Amazon.com took some heat over privacy concerns for a week or so after the purchase circles appeared. People worried that Web surfers could pull up their account data, and companies fretted that their employees' reading habits might reflect poorly upon them.
With a couple of clicks, customers can tell Amazon.com not to include their purchases in the purchase circles. Companies can fax requests on an official letterhead for their information to be removed as well, Capelli said.
All the science that goes into producing the lists makes for some interesting reading about reading.
On the best-seller list in Merchantville, Camden County, is a story about the Apocalypse, Left Behind: A Novel of the Earth's Last Days, a retelling of the biblical chapter of Revelations. It features an airline pilot who notices that many of his passengers have disappeared when the Rapture comes and some people are spirited off to heaven. Though the book is selling well nationally, around Philadelphia it appears only in Merchantville's purchase circle.
Mayor Patrick Brennan at first seemed flabbergasted on hearing what his constituents had been reading.
"I would just have to think it's . . . I don't know," he said.
But then Brennan reflected on the number of churches and active church members in his borough and decided it made sense.
In Wyncote, Montgomery County, The Language of Truth: The Torah Commentary of Sefat Emet is a big seller, topping two selections from the Oprah Winfrey book club and coming in at No. 6. Not bad for 408 pages of 100-year-old Torah commentary, translated from Hebrew.
That is perhaps not entirely shocking, given that nearby Elkins Park has a flourishing Jewish community that just put up an eruv, or a ritual fence, around the area to help Orthodox Jews there obey Sabbath restrictions.
In Voorhees, Camden County, Dave Pelz's Short Game Bible: Master the Finesse Swing and Lower Your Score sells well - and only in Voorhees. Mayor Gary Finger said he expected that, joking that he is the township's only resident who does not play golf.
Much less quirkiness shows through in the video and CD choices. In just about every place around the area, the kick-boxing Tae Bo Workout is the top-selling video, followed mostly by newly released Hollywood blockbusters. In Woodbury, Gloucester County, however, the No. 2 video is Gone With the Wind. Hot CDs were a mixed bag: Dave Matthews and U2 in Villanova, Lauryn Hill and the Buena Vista Social Club in Philadelphia, Sarah McLachlan and Ricky Martin in Mount Laurel.
Overall, the region seems to be reading pretty much what everyone else in the country is reading. Best-selling children's books about the teenage wizard Harry Potter show up in every town. John Grisham's and Tom Wolfe's works duel with Hannibal Lecter and Memoirs of a Geisha around the Philadelphia region, just as they do elsewhere. It is true even in Hershey, home of everything chocolate. The No. 1 book on the list there is The Emperors of Chocolate: Inside the Secret World of Hershey and Mars. But what shows up farther down?
Sugar Busters! Cut Sugar to Trim Fat.