Analysing Site Speed in 700 Top eCommerce Sites - Kaizen

Why is site speed
a concern?

Web-users are not patient. The speed of your site can make a massive difference to whether people will visit your site, whether they’ll stay on it, and whether they will come back. Not to mention whether they’ll make a purchase.

A massive 79% of shoppers who have been disappointed by a site’s performance say that they’re less likely to use the site again. But what constitutes ‘disappointed’?

We're only human after all

The Kissmetrics research on customer reactions to site speed has resounded across the industry, but it’s not something that should be forgotten:

“If an e-commerce site is making $100,000 per day, a 1 second page delay could potentially cost you $2.5 million in lost sales every year.”

That’s a 7% reduction in your conversion rate, and 52% of customers say site speed is a big factor in their site loyalty. A one second delay is bad – a two second delay is worse. 47% of consumers expect web pages to load within two seconds.

Page load and page abandonment
Page load and page abandonment graphic Page load and page abandonment graphic Loading Time (Seconds)

Thankfully, as much as a slow page is bad, a fast one is good. Based on the same research, a faster full-site load leads to a 34% lower bounce rate, and an improvement by just one second results in a 27% conversion rate increase.

Bounce Rate and Loading Time
Bounce Rate and Loading Time graphic Bounce Rate and Loading Time graphic

But if you hold onto legacy technology and your site remains old and slow, you’re going to lose customers and risk being superseded by competitors or apps, or just forgotten about by your target audience. Site speed has been a Google ranking factor since 2010 - sites still running slowly since then are lucky if potential customers find it through search at all.

It’s because site speed is such a vital part of building a successful eCommerce site that we’ve conducted a study into 700 top UK eCommerce sites, analysing various aspects of their site speed performance. What we found is that major brands have some of the poorest optimisation on the web. We found problems like outdated web protocols, unresponsive pages, and bloated web-page size.

The average web page size is now 2.3MB (fun fact: that’s the size of the shareware version of the classic computer game Doom), so we wanted to see whether the ecommerce industry are any better – since their businesses are directly dependent on their website performance. Surprisingly, we have found that the web page size of the top UK ecommerce sites is 35% bigger on average than standard websites – at 3.1 MB.

Total transfer size per page
Total transfer size per page graphic Total transfer size per page graphic