This document discusses how small design factors can influence conversion rates on websites. It provides examples of how websites like Walmart, Staples, and Intuit improved their conversion rates by 1-14% by reducing load times by 1-2 seconds. The document also discusses an experiment by Fanatics where reducing median page load times by 2 seconds nearly doubled mobile conversions. It identifies issues like inefficient images, blocking page loads, and unoptimized CSS/JavaScript that can impact performance. The key takeaways are that user expectations change, performance issues are unpredictable, you need to measure factors, optimizations can create new problems, and small improvements can make a big difference.

1. The Small Things That Add Up
How to Find out What Design Factors Influence Conversions

2. Joseph Paulling Tammy Everts
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3. Web performance
is user experience

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Source: Akamai#IRCE16

6. Source: Akamai#IRCE16

7. Lenny Rachitsky, Product Manager
“Downtime is better for a B2C
web service than slowness.
Slowness makes you hate using
the service. Downtime you just
try again later.”
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8. Web performance
is ecommerce success

9. Every 1 second of load time improvement
equals a 2% conversion rate increase for
Walmart.com
Staples.com shaves 1 second from median
load time, improves conversion rate by 10%
Intuit cuts load times by more than half,
increases conversions by 14%
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10. Lara Hogan, Senior Engineering Manager
“We ran this experiment on mobile web
where we added 160 kilobytes of hidden images,
meaning the user saw nothing different.
We just dumped a bunch of hidden images onto the
page and increased page weight by 160 kilobytes.
It triggered a 12% increase in bounce rate.
Insane. Twelve percent is a lot of percent.”
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fast
slow
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14. Web performance
at Fanatics

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2-second improvement
in median page load time
almost doubled mobile conversions
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23 May 2015 22 June 2015
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front-end load time
back-end load time
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21. Issue #1
Image quality and
compression
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Average website

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Fanatics

24. Issue #2
Image sprite
blocking page load
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Reformat
Resize
Compress
Defer/lazy load
Cache
More image
optimization solutions

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28. Issue #3
Unoptimized
CSS and JavaScript
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Consolidate page resources
Make sure stylesheets are in the
document HEAD
Optimize web fonts
Optimize pop-up scripts
Monitor third parties
More optimization
solutions

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http://www.webpagetest.org/

32. Takeaways

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1 User expectations and behavior are
always changing
2 Performance issues are unpredictable
3 You can’t know what you don’t measure
4 Solutions can create new problems
5 Grab the low-hanging fruit: optimize your
images
6 Even small performance improvements
can make a big difference
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34. Thanks!
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