From the perspective of Macy's owner—Federated Department Stores Inc., which also owns Bloomingdales—the only problem was the one hour the site was fully down. "We were doing business all day," said Jim Sluzewski, Federated's vice-president for corporate communications.

On Tuesday (Nov. 28), the site crashed again, starting at about 4:30 PM, Sluzewski said, and the site came back at 5:45 PM "when we rebooted the server. It was a hardware issue."

But services that monitor Web traffic again saw that crash preceded by errors and dramatically slower response times.

Macys is only the latest example of a frightening trend among E-Commerce players, including some of the industry's largest retailers. They see Web traffic in black-and-white terms, with the site either being up or down, with nothing inbetween. Users, however, tend to look at it quite differently. They see the site either as fast and responsive or not. If the user has to wait 30 seconds for a page to load, that user will declare the site down and will click to a rival's site. The fact that the server might merely be running slowly doesn't mean much to the guy in Toledo who wants to buy a new refrigerator.

We already know that online shoppers today are trigger-happy to click away to a rival at the slightest slight and that they'll frequently punish the brick-and-mortar brand for sins committed by the online cousin. But household-name retailers days away from December 2006 being blissfully ignorant of huge site slowdowns? How rampant can this be?

Ben Rushlo, who watches E-Commerce activity all across the country for Keynote Systems, wasn't surprised by the trend when reached late Wednesday, despite the fact that consumers know it instantly. "You can't argue that a 10X slowdown is not noticeable," Rushlo said. I guess the site owner is always the last to know.

"I just had a long E-mail conversation with a major retailer site that had exactly that attitude. They said something like, "We had record sales during that period.' My point was that while you might have had some users who got through, you were really having an impact on even greater revenue. So the argument that some people got through (or even a record number got through) doesn't work because of all the other people who wouldn't have abandoned or would have purchased if you hadn't had a performance meltdown," he said. "We do not think that users will be ok with waiting 30 seconds for something that takes normally two seconds on the site or will only take two seconds on a competitor's site. As the Internet becomes more of a utility, users are becoming less and less tolerant of slowdowns like this."

Let's be precise about this. The immediate concern is not that retailers are fine with letting their sites get super slow. A handful do indeed feel that way, but that's not the case with most large retailers. No, the concern is that far too many retailers are blissfully unaware of their site performance if their internal (behind the firewall) indicators show that all is well.

"My gut feeling is that the obliviousness is still out there for a large percentage" of major retailers, said Imad Mouline, the chief technology officer for Gomez, another Web traffic tracking site.

Mouline said the problem stems from how most E-Commerce managers see the world. "A lot of these sites are simply looking at it from the inside, checking out the load on the Web server," he said. "That's honestly just absurd. It's not the whole picture."

First, performance behind the firewall—in immediate proximity to the main server—will always be slightly faster. Secondly, much of the content for the largest E-Commerce sites is not residing on the retailer's servers, with everything from third-party services (for checkout, shipping and some aspects of security) to third-party content for additional products being offered by partners. "Some of these sites can have six, seven or eight (of these third-parties) and it can be a cascading event when any of these third-parties slow down," Mouline said.

These are all things that the retailer could impact if only the retailer knew. Let's not even get into the mountain of issues that the retailer cannot possibly impact that can also dramatically slow down a purchase experience, such as slowdowns at the customer's ISP, the Internet in general, the local area around the consumer (for shared connections, such as cable modems) and even the consumer's machine (RAM, hard-disk, CPU, browser and third-party software can all dramatically impact the site's perceived speed).

The most frightening retail defenses are also among the most common. Defense/Excuse One: "Our site can't be seriously slowed down. Look at all the sales we're making this afternoon." Beyond the correct point that Rushlo made about the inability to know how many additional sales would have been made had the site been operating properly, there's a bigger issue. How happy are those customers? Were they thrilled with the easy and effortless experience? Or were they frustrated and resentful and pledged that, if they can only get through this checkout, they're never coming back again?

People talk about E-Commerce sites being able to replicate all of the features of a brick-and-mortar, but adding 1,000 more. In this instance, though, a myopic nature of an E-Commerce comes through. At a physical store, associates and floor managers know when customers are upset. As lines get long and the parking lot gets overfilled, people are not shy about voicing their frustration. Online, however, few sites make it easy to do so. There's rarely a space next to Zip Code asking "How are we doing?"

This brings us to Defense/Excuse Two: "I know that customer problems are isolated. Otherwise, I'd be getting lots of complaints from our customers." When it's been a long and frustrating shopping experience, few consumers will take the time to craft a helpful note about the problem. Even were some inclined to do so, few retailers make it easy.

There are a lot of ways to improve online customer interaction, but a great place to start is accept the fact that a slow site is worse than a crashed site. At least with a crashed site, retailers know there's an immediate problem to fix. Retailers, take note: Ignorance of your true site performance is going to kill more of your sales than an army of viruses.