Following the release of the Hitwise 100 list from IMRG and Experian, Mick McGuiness of Application Performance undertook some interesting analysis of the top sites. Here he explains the tests he did and the results that emerged.

The Hitwise list records the top 100 e-commerce sites in terms of volumes of traffic.  Application Performance specialises in helping customers optimise site performance and we discovered some interesting results following our tests ... 

• The page load speeds difference between the best and worst performing sites is huge
• By following best practices for web content performance optimization big improvements could be made, for example ...
• 73 of the top 100 sites could be at least 30% quicker.
• On average the sites could be more than 40% quicker.
• The key criteria for being in the top 5% are listed in the report.

Methodology

The testing methodology we followed was to use the well-respected WebPageTest.org for our measurements and we used IE7, 1.5MBps and averaged over 3 page loads.

Variability in page load speeds

• Best – 1.6 seconds
• Top 5% - 2.7 seconds
• Average – 7.5 seconds
• Worst – 20.9 seconds

The results shown in this diagram relate to first time visit speeds, where the visitor had nothing cached in their browser and is critical for the all-important first impression.

The variation in actual page load times was huge from less than 2 seconds to more than 20. So, just to be clear – there are sites in the top 100 e-commerce sites that are taking at least 10 times longer than the fastest-performing sites to appear. Just consider the impact in terms of customer experience and bounce rate.

In addition, page render times varied considerably – if you look at the diagram, each thumbnail constitutes a half-second of load time. However the ‘blank’ thumbnails show the time before the page renders for the customer – some taking up to 5 seconds before anything appears on screen giving the perceived appearance of the site being even slower.

Repeat page loads

The time to load a repeat page is indicative of what it would take for a returning customer.

• Best – 0.3 seconds
• Top 5% - 0.9 seconds
• Average – 3.7 seconds
• Worst – 20.4 seconds

What is particularly interesting here is that the worst performing site has a page speed that is almost identical to a first page load time, where better performing sites show considerably shorter load times.

Page size and number of objects

Size...

• Best – 83k
• Top 5% - 248k
• Average – 671k
• Worst – 2Mb

Objects ...

• Best –13
• Top 5% - 21
• Average – 78
• Worst – 169

Large pages will take longer to load and the difference between best and worst performers becomes clear with page sizes of over 2Mb compares to 83k. Likewise, the number of objects being downloaded will have a considerable impact; heavy pages with many objects will take longer to load.

Best practice and the top 5%

Looking at these figures, it is unrealistic to imagine that all e-commerce providers can aspire to the top performer in all cases. We would also argue that the average is too far adrift from the top performers to set a best practice level.

Our recommendation for best practice would be to aim for the 5th percentile

• First time page load –2.7 seconds or less
• Repeat page load time –0.9 seconds or less
• Page size –248k or less
• Page objects – 21 or less

On this basis:

• Three quarters of the top 100 need to reduce page load times by 30% to get into the to 5%.
• On average, sites could be 40% quicker by applying best practices.

The importance of speed in the e-commerce environment

There are numerous reports you can find on the internet which demonstrate the importance of fast page load times and the impact that speed has on the conversation rates and revenues for e-commerce sites.

However, common sense dictates that speed will drive customer experience, and a favourable customer experience will lead to...

• More time spent shopping rather than navigating
• More return visits
• More recommendations   

Video walk through

Watch the video walk through of the Hitwise report to get more detail.

Download the Report

We intend to continue to monitor the Hitwise 100. If would like to download the report or want to sign up for quarterly updates click here>>

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