The Financial Times recently conducted valuable research studies to understand how website speed influences consumer engagement and its overall impact on revenue.

Their first study was conducted among subscribers, selected at random, for a control group and a test group. The control group saw their website at normal speed and the test group saw the site with a five-second delay added to each page load. Important to note, the 5 second delay was in addition to FT’s normal load time. The first test showed a significant drop in engagement in the control group compared to the test group.

The Financial Times then conducted a second study but this time they segmented subscribers into four groups. There was a control group, the same as before with the website at the usual speed, the second group saw the website at 1 second delay in page load, the third group saw the website at 2 second delay and the third group saw the website at 3 second delay. As well, FT was able to look at these tests group by device (mobile, tablet, desktop) by historical subscriber level of engagement (high medium and low) and by time (day/month).

The analysis was based on session depth which identifies the number of pages a subscriber views during a visit. FT used session depth as their conversion rate and calculated the difference test groups. FT found that short visits had little to no impact across the test groups. However, for subscribers visiting more than three pages, there was a gradual decline in engagement across each test groups. In fact, over the testing period subscribers read fewer articles given the laps in loading each web page. Interestingly, the research also found that both very loyal subscribers as well as mobile users were more tolerant of site delays.

Importantly, the research suggests a strong correlation between a site’s speed and its impact on both sessions depth and the number of articles read. In other words, the slower the page loading time the greater the negative impact, regardless of how small the delay. In FT’s case, engagement directly impacts subscriptions so there is a clear correlation to revenue. Further since FT sells based on page views and time spent with each advertisement, the more time spent on the site the greater impact on advertising revenues

Complete article: http://engineroom.ft.com/2016/04/04/a-faster-ft-com/