The goal of monitoring performance is to ensure that, at any given time, your site is available to visitors and that your pages load quickly. There are numerous ways to measure the performance of a site, and an increasing number of tools and services can help. Use this checklist to learn what aspects of performance are critical to e-commerce success, so you can choose the monitoring method that's right for your business.
Essentially, Web performance monitoring consists of measuring various components of a site's performance at regular intervals. How do you know exactly what a monitoring program should measure? Think about the real-world equivalent of your online business, a brick-and-mortar store. In order to have a satisfying shopping experience, customers must be able to get into the store, move around the sales floor without hindrance, and view merchandise quickly and conveniently.
Thus, for your Web store, you need to ensure four things above all else:
Your site must be accessible to visitors.
Your Web server(s) must respond quickly and accurately to page view requests.
Your pages - especially those displaying merchandise - must appear without significant delay.
Your links - whether internal or external - must all be in working order.
The metrics that correspond to the first three of these goals, respectively, are downtime, response time, and download time. The following checklist explores the significance of each measurement and suggests appropriate monitoring methods to help you accomplish all four of these goals.
Monitor Your Web Site's Downtime If you've ever calculated how much revenue your Web store generates per day, per hour, or even per minute, then you know how important it is that your site is always "up" - that is, available to customers. To understand the full impact of downtime - or site crashes, as they are often referred to in the media - consider one of the heavy e-commerce hitters, such as Dell, that depends almost solely on its Web site for revenue. InternetWeek reports that downtime of just one minute could cost sites such as Dell's as much as $10,000: "By that count, a two-hour blackout carries a price tag of $1.2 million." Even if you won't suffer five-digit revenue losses when your site goes down, you might pay a much higher price in the long run by alienating customers and permanently damaging your e-commerce credibility. Fortunately, downtime is one of the easiest metrics to monitor and to control.
Monitor Your Web Site's Response Time A potential customer has just clicked on your site's URL. How long will the surfer wait for something to appear in the browser window? According to statistics from GartnerGroup, Internet surfers will wait no more than 20 seconds, and that's if they're convinced that the site is really what they want to see. The standard accepted wait time is a much less forgiving eight seconds. The Internet layperson might confuse "response time" with "download time," which is described below, since to the end user they mean essentially the same thing: the time it takes to see something happen on the screen. But from a monitoring perspective, they are very different. In order to stay on top of response times, you must know exactly what you are monitoring and how to use the data your monitoring generates in order to avoid exhausting your customers' patience.
Monitor Your Web Site's Download Time Many people think of download time as the entire time that passes between requesting a page (clicking on a URL) and seeing that page fully displayed in the browser window. While this waiting period is actually composed of response time in addition to download time, the latter normally uses most of those seconds. For this reason, download time is almost always to blame for slow pages. So, even if you've taken steps to ensure that your site is up and that it responds quickly, your monitoring efforts are not complete without looking into download times. Most Web sites contain many components, and therefore many things that can negatively affect the speed at which the pages load. Fortunately, many current monitoring tools and services allow you to pinpoint exactly what is slowing your pages.
Monitor Your Web Site's Links We've all had the experience of eagerly surfing through a site, only to click on a link that returns an error message or a blank page. Nothing undermines the credibility of a site quite like such an abrupt dead end. Since all but the most rudimentary Web sites contain numerous links, chances are that your site, too, poses a potential threat to smooth surfing. Whether your links are "internal" (taking visitors to another location within your site) or "external" (taking visitors to another site altogether), they can break for a variety of reasons. Therefore, checking links on a continual basis is an important part of performance monitoring. And because it's also one of the simplest and least expensive monitoring processes, there's no reason your customers should ever be derailed as they click through your site.