Evan Schuman's StorefrontBacktalk

The old rules for speeding up E-Commerce Web sites are toast. That’s the clear conclusion to draw from a new Pingdom study, released on Tuesday (June 19), comparing performance of the top 100 E-Commerce sites—including dozens of big retail-chain sites. Some fat sites are fast anyway. Some lightweight sites are surprisingly slow. And what’s really killing performance seems to be metrics.

The good news: Virtually all the large retailers got their response times down under the fabled three-second mark. The bad news: There’s no longer a clear correlation between speed and site size and the number of files requested, the variables that Pingdom tracked in this study.

The chains with the fastest sites—we knew you were waiting for this—are Forever 21 (#2 out of 100), IKEA (#4), Walgreens (#5), REI (#6), Kohl’s (#7) and Bloomingdale’s (#10). Bringing up the rear is Neiman Marcus (#92), which along with Victoria’s Secret (#89) and Bed Bath and Beyond (#86) had the only sites that took more than three seconds to load.

Among other major chains, Walmart (#57), Target (#60) and CVS (#81) were top-10 chains that fell in the bottom half of the rankings, behind Best Buy (#13), Lowes (#24), Home Depot (#28), Sears (#32) and Kmart (#39). Amazon was #20. (A link to the complete list is here.)

But enough of the horse race. What’s much more interesting about the results is how random they appear, at least according to conventional Web site performance wisdom. Pingdom headlined its survey report “Slim and trim to slow and bloated—the top 100 E-Commerce websites,” but that’s a little misleading. Two of the fastest sites (REI.com and Kohls.com) are also among the most bloated, as measured by the amount of data that has to be downloaded—they’re more than twice the size of an average site in the study.

That’s not the only place the old smaller-is-faster paradigm falls apart. Yes, IKEA has a slim site that’s also fast. Forever 21 is even faster, but it comes in at #62 for slimness—it’s heftier than average.

Meanwhile, Saks Fifth Avenue has one of the smallest sites, but it’s only #49 for speed. And CVS, at just over half the average size, is simply slow compared to almost all the other retailers.

True, some of the smaller sites perform faster. But smaller-is-faster is no longer a reliable rule—if it ever was.

Ironically, what’s slowing down some of the big-chain sites are calls out to third parties—such as Web metrics and tracking services—that drag down site load times but are outside the control of retailers.