Urban Outfitters Inc., the South Philadelphia-based women's retail group, has cut its online delivery time below four days - from six last year - since opening its new "fulfillment center" in Gap, Lancaster County, says StellaService, a three-year-old New York firm that tracks how Internet retailers deliver the stuff they sell.

StellaService says its latest sampling shows Urban Outfitters delivered faster than online-retail industry leader Amazon.com, on average, during April.

The firm was founded by Bucknell University roommates Jordy Leiser and John Ernsberger, with support from Diapers.com founder Marc Lore, Ty McMahan, director of content for StellaService, tells me. Lore has been a mentor to fellow Bucknell entrepreneurs since he sold his business to Amazon for more than $500 million in 2010.

StellaService offers an online extension of an old practice: mystery shopping. The firm says it has hundreds of delivery testers, audited by KPMG, helping clients such as Target figure out how fast Sears or Overstock.com are moving product, as well as tracing new software orders and warehouse staffing.

Retailers need independent data to check their own performance vs. their rivals, says Anthony Bucci, cofounder at motorcycle-gear marketer and distributor RevZilla, which is based, like Urban Outfitters, in the former Philadelphia Navy Yard business park. StellaService helps RevZilla with tough-to-measure customer, warranty and shipping data. There are many new metrics to track, Bucci said, in the "experience economy." (From my column in today's Philadelphia Inquirer)