Performance and conversion are inextricably connected

Slow pages cause abandonments
According to AnnexCloud, a slow website can increase abandonment by 75%, and loyalty drops 50% when your site is slow. (source)
AliExpress shared that reducing the load time of their pages by 36% yielded a 10.5% increase in orders and 27% increase in conversion rates for new customers. On the other hand, by improving render time by 68%, load time by 64%, and page weight by 46%, Ancestory.com saw a 7% increase in conversions. (source)
Amazon has shown that each 100ms of latency costs them 1% in sales. Walmart chalks up an extra 2% conversions with every second of performance improvement. Any online shopper will tell you that faster is better than slower.
A 2013 study of the effects of mobile web performance on user emotional engagement found that a mere 500 millisecond delay resulted in a 26% increase in user frustration, and an 8% drop in engagement.
A study by Skilled from 2016 found that:
- 79% of customers “dissatisfied” with web performance are less likely to buy again.
- 64% of smartphone users expect a website to load in four seconds or less
- 47% of online shoppers expect webpages to load in two seconds or less
- If your site makes $100K per day, a 1 second improvement in page speed brings an additional $7K in revenue
- A 1 second delay in page load time means 11% loss of page views
- A 1 second delay means a 7% reduction in conversions
Also check out Neil Patel’s infographic on how loading time affects your bottom line
Shopify’s advice
Shopify recommends these 12 improvements to optimize your store’s loading speed:
- Use fast and reliable hosting
- Use a CDN
- Use Google Tag Manager for your tracking
- Prioritize testing and optimizing your mobile performance
- Minimize your use of quick view windows
- Minimize the use of Liquid forloops
- Use Shopify’s built-in image size parameters to minimize thumbnail sizes
- Eliminate or minimize homepage hero slides
- Remove any apps you’re not using
- Compress and reduce images in size and number.
- Compress with TinyPNG, TinyJPB, or one of the many Shopify apps available
- Minify your code
- Reduce redirects and broken links
Google’s advice
According to Google, the two factors that lower conversions are: the number of page elements, and the number of images.
As for the bounce rate (meaning the percentage of people that leave your site without exploring beyond the first page), the main factor is speed. Google advises to set a “performance budget” for your pages. For example, if you decide that they should load in 3 seconds, then simplify your pages until the load time is under that threshold. And avoid using JavaScript if possible.
Test your loading speed
- Google PageSpeed Insights (desktop & mobile)
- Google Test My Site (mobile)
- GTMetrix
Some nuance
One of the members of my Ecom Convert group suggested this:
A less technical work-around is to install a ‘Please wait while page is loading…’ modal popup or separate page to display until all elements of the checkout page are loaded. With a Font Awesome spinning cog or a light animated gif, the customer will stare at it and patiently wait until the page is loaded.
Skeleton screens
Otherwise, you can give the impression that pages load faster with skeleton screens. Unlike animated loading spinners that focus user attention on the fact of data loading, skeleton screens focus user attention on progress instead of wait times.
GrowCode’s advice
- Utilize page caching
- Optimize images and CDNs (content delivery networks) to serve static content
- Limit redirects
- Minimize scripts
- Compress images
(source)