By Imad Mouline, Chief Technology Officer, Gomez

A decade ago, there was an “8-second rule,” the time a person would wait for a web page to load before leaving. Now surveys show this is less than three seconds.

Some executives can’t imagine that a few seconds wait time can hurt their business. This is a mistake, according to a 2008 report from technology research firm Aberdeen Group, “Customers are Won or Lost in One Second,” which said that a one-second delay could mean a 7% reduction in completed sales. For a $100,000-a-day e-commerce site, that’s $2.5 million in lost yearly revenues.

The good news is that you can solve website performance problems, usually before customers notice. You just have to know where to look. Here are some key roadblocks:

• Website complexity: Your customers want speed, but they also want features, like graphics and video — which can slow a site. The impact of these features must be tested before the site launches, and monitored afterwards.
• Regional differences: Site performance lags the farther a customer is located from the host server. This is why content delivery networks (CDNs), which place duplicate servers closer to customers, are popular. Even with CDNs, you have to monitor your site’s speed on a region-by-region, even a city-by-city basis.
• Browser incompatibilities: When Internet Explorer was the dominant web browser, it was easy for IT departments to optimize for it. Now there are multiple Explorer versions, two or three other major browsers, and many niche browsers. Each handles website code a little differently, which can affect how fast a site loads.
• Third-party content: Most of today’s websites include content that’s hosted outside of your server, such as ad networks, video feeds or analytics tags. If these slow your site, customers will only blame you.
• Mobile applications: According to a recent study, 58% of mobile device users expect sites to download as quickly as on their home computers, so businesses need to test download speed on other devices as well.

If your company wants to avoid these problems, consider the best practices we’ve seen adopted by industry leaders:

• Benchmark the competition: First research how quickly your competitors’ sites load, then you’ll have a reference point. But don’t limit site comparisons to the competition, since most users will also judge it against big sites such as Google (GOOG) and Amazon (AMZN).
• Measure from your customers’ perspective: Sometimes problems can occur between your data center and the customer’s browser. The hardware, software, and services that sit between you and your customers is known as the Web Application Delivery Chain. If your monitoring tools measure from the outside-in — from your customers’ browsers — you’ll know exactly the performance they are experiencing. If you just measure from inside your firewall, you only have a partial view.
• Recognize Web performance as a business issue: Poor web performance can directly impact revenues, so IT and business departments need to work together to improve web performance. If a new feature affects how well the website loads, its rollout becomes a shared decision between IT and business.

More executives now understand the downside and upside of web performance. Those that do will enjoy a competitive advantage, and they’ll be ready for the day when we’ll all be talking about the “half-second rule.

—Gomez is the the web performance division of Compuware (CPWR).