At every step along the digital path, retailers accelerate site performance

Online retailers face a double whammy: At the same time as consumers expect more rich features on e-commerce sites, they also want those sites to be faster than ever. Even as retail sites have added bandwidth-clogging features like video, zoom and animated content in recent years, consumers have become less willing to wait for pages to load.

While most online shoppers said in a 2006 survey they would wait 4 seconds for a site to load, when the survey was repeated this summer 47% said they grow impatient when web pages take more than 2 seconds to load.

And least patient are those who shop the most: 61% of those who spend more than $1,500 a year online rated response time as important in determining where they shop, versus 52% for all shoppers, according to the survey by research and consulting firm Forrester Research Inc. and Akamai Technologies Inc., whose global network of servers speeds the delivery of web content.

Retailers need not despair, says Mike Gualtieri, senior analyst at Forrester who specializes in web site performance. "The bad news is that customers want richer content and Internet retailers have to provide it," he says. "The good news is that improvements in technology allow smarter companies to mitigate the impact on site response."

With the approaching holiday season sure to dramatically increase traffic to e-commerce sites, here are five tips for improving site performance. And some of them don't cost a lot of money.

1. Cache as cache can

Many online retailers are aware of content delivery networks that store content on geographically dispersed servers to speed up delivery. But some may not know about the caching resources of their own e-commerce applications.

Sophisticated e-retail platforms can cache commonly requested content, and making use of that resource is one of several steps musical instruments retailer Sam Ash Music Corp. took to reduce demand on its servers and improve site performance, says Igor Gorin, CEO of SysIQ, which hosts the IBM WebSphere platform that SamAsh.com moved to a year ago.

The internal cache of an e-commerce application can store, for instance, a frequently viewed product detail page, Gorin says. To assemble that page from scratch requires reaching into various databases to pull out product name, description, images, price, customer reviews and more. All those trips to and from databases take time. Storing the assembled code of a page in the cache of the e-commerce platform can reduce page loading time from several seconds to less than a second, he says.

When SamAsh.com was on a previous e-commerce platform and using a different site host, company CEO David Ash once had to post an apology to customers for poor site performance. By moving to the IBM WebSphere e-commerce platform, and employing SysIQ--which was familiar with WebSphere--apologies are no longer required, Ash says.

The modern web browsers consumers use now also have considerable caching resources that can speed response times, Gualtieri says. Browsers can store commonly used elements of a web page, such as the logos that appear on every page, so they don't have to be downloaded when the consumer moves to a new page. "But the programmer has to tell the browser to cache that information," Gualtieri says. "It doesn't happen automatically."

The third common form of caching is to store frequently requested content in the servers of content delivery networks like Akamai and Limelight Networks.

Online jewelry auction site Bidz.com turned to Akamai this summer to accelerate site performance, primarily for overseas customers, and so it could add video to its site.

Pages load about twice as fast now for customers in key Bidz.com markets such as Saudi Arabia, Germany and South America, says Leon Kuperman, president and chief technology officer.

While caching is one big reason, Kuperman also says Akamai can retrieve quickly data that has to be kept centrally on Bidz.com servers--such as bids in an auction--by maintaining always-on connections to the retailer and monitoring the Internet to find the fastest path to the Bidz.com data center.

2. Cut out the fat

When it comes to site performance, every byte counts: the fewer bytes servers have to deliver, the faster a page will load.

Retailers can thin down pages by being smarter about how they employ JavaScript, a programming language that site operators use for web tasks like rotating an item or validating a ZIP code, and style sheets, which control the look of a site.

Often site developers seeking to add a function, such as address field validation, will download an entire standard JavaScript library developed for that purpose. But that library may include 20 routines when a site uses only five, says Matt Poepsel, vice president of performance strategies at Gomez Inc., which monitors web site performance.

"Retailers should take out the ones they don't need," Poepsel says. JavaScript can account for as much as 20% of the content of a web page.

Style sheets also can be compressed. Poepsel recently wrote on the Gomez blog about a free tool called Code Beautifier that analyzes a site's use of style sheets. In the example Poepsel cited, the tool suggested ways to slim down style sheet content by more than a third.

While images often are in formats such as JPG that are already compressed, experts say retailers should monitor their use.

At Ritz Interactive Inc., which operates e-commerce sites RitzCamera.com and BoatersWorld.com, merchandisers select product images and are not always paying attention to their impact on site performance, says Mark Remington, chief technology officer. The Gomez site-monitoring service Ritz uses can identify precisely what part of a page is loading slowly, which helps Remington identify unusually heavy images that slow response times.

Site designers sometimes want to put text into image files so they can present messages with artistic flair, says Simon Rodrigue, assistant vice president of e-commerce at Sears Canada. But those images add more to page weight than standard HTML text. Unless the graphical presentation improves conversion, he suggests, skip the image and stick to text.

3. Find the best route

Retailers often have several connections from their data centers to the web so they can keep operating if one fails and so they can use lower-cost connections whenever possible.

Nanette Lepore, a retailer of women's fashion apparel, uses three such connections and employs the PowerLink 100 Pro device from Ecessa to route traffic to the pipe that offers the best performance at any time, says Jose Cruz, I.T. director at the retailer.

Besides maximizing performance, the device can prevent site failures. In one case, when a construction crew cut a landline connection, the device switched traffic to the retailer's wireless connection, keeping the site up.

In another, a denial-of-service attack by hackers coming in on one Internet link drove up traffic and spilled over to the other two, slowing down the site. PowerLink enabled the retailer to shut down the link under attack, allowing the other two web connections to resume normal operation. The PowerLink 100 device is priced at $2,995.

4. Test the weakest link ...

Many retailers test their sites in advance of the holiday season by simulating the load that many individuals accessing the site simultaneously create. But concurrent users isn't necessarily the key metric for every retailer.

One large retail chain is most concerned about the capacity of its order management system. So testing service Keynote Systems Inc. has been putting that system to the test, simulating the load of many transactions going through the entire checkout process, using nonworking credit card numbers, says Donald Foss, director of Keynote's global testing service, who declines to name the retailer client.

It's also important to test a site with a realistic mix of the actions consumers initiate at a site, such as browsing, searching and purchasing, says Rodrigue of Sears Canada. Rodrigue says he has seen in past jobs cases of surprising results--such as an unexpected failure of the site's database layer--that weren't predicted by the modeling site engineers had done in advance.

5. ... and test until it breaks

A site crash is usually a disaster, but some large retail chains intentionally crash their sites in the months leading up to the holiday season. They just do it in the middle of the night when few people shop.

The point is to understand the capacity of the site, and to make sure crucial features will stand up to heavy loads. While he would not mention the retailers by name, Foss of Keynote Systems says one large chain has been applying exceptionally heavy loads to its site every other Friday night and another every Wednesday night, both in the wee hours. While the sites don't always crash, they sometimes do, and usually are brought back up within 10 minutes, Foss says.

It's important to test any new feature in a production environment--and not just on a server off to the side--because that's the only way to know how the new functionality will stand up when working alongside all the other components of the site.

"We will overload the amount of concurrent users or page views and see what breaks first," he says. "Then we make an effort to understand why the failure occurred, fix it and break it again. When launching new functionality it's important to understand where the weak links are."

Finding weak links in the middle of a summer's night is surely better for an e-retailer than discovering them the day after Thanksgiving.