JCPenney's decision to build a complete online store within Facebook, where you can not just browse products but buy them too, is as sinister as it is gimmicky. The benefits for the department store are twofold: more sales driven by product visibility in people's news feeds, and more information about its customers. Said information includes their age, taste in products and how often/where they browse, all of which "can be aggregated into analytical data," according to Usable spokesperson Jason Taylor. (Usable built Penny's Facebook storefront.) Other companies—Proctor & Gamble, 1-800-Flowers, etc.—have product catalogs on Facebook, but Penney has outdone them all. At what cost, though? Facebook is the last place I'd want my credit-card information stored (I don't even have my last name on my profile), and this move just further exposes Facebook as a two-way mirror through which marketers and employers spy on the layfolk. None of which matters much to Penney at this point, and I suspect sales will increase simply because they got here before everyone else did. But they're a little too high on their chances of sustaining it once hipper stores climb aboard.