Until a few years ago, the way we all were using the web was different. The first step was always to go on a website front page, and from there navigate until we reached the desired product or article. Google role, at the time, was mainly to help us find the relevant website and it was on us to find the right page.
Nowadays the process is radically different. We trust Google to pick the right page for us, regardless of the website that is hosting it. With a single click we land on the page and with a quick look, we can confirm if where we are is what we want or if we need to keep searching. Another option is a slow page that doesn’t allow us to assess the relevance. Both wrong and slow pages trigger the same action: we simply go back to Google.
Google detects the click-back-click pattern. When the pattern shows up for the same webpage multiple times, Google infers that the page is not a good match for the search and therefore lower the page ranking.
There a general consensus that the minimum threshold is 2 seconds. If after 2 seconds the page is not visible and responsive (clickable and scrollable) the visitor is likely to go back to Google and select a different page. Having your eCommerce website performing below 2 seconds can be challenging for complex pages even when the visitor is on a desktop computer. It can become extremely difficult when the visitor is on a mobile device.
Speed is not only affecting the user experience and perception, but also the page ranking. A slow page can quickly disappear from the organic search results regardless of the content quality and keywords use. All SEO improvements can be erased by a slow website performance.