Slides from my talk at Bristol WebPerf Meetup 2017-07-20 where I talked about some of the approaches I use to persuade people that they should invest in making their sites faster
Andy DaviesIndependent Web Performance Consultant at Asteno
5. But it’s not just about getting visitors to buy things!
- sign ups / subscriptions
- completing tasks
- interaction with adverts
- sharing things
- finding a store / restaurant
- reducing costs - hosting / acquisition
7. Response Time in Man-computer Conversational Transactions
Robert B. Miller, 1968
Instant
Seamless
Yawn!
100ms 1s 10s
How we perceive response times
8. Response Time in Man-computer Conversational Transactions
Robert B. Miller, 1968
Instant
Seamless
Yawn!
100ms 1s 10s
Median start render time for 600+ UK retailers = 1.68s
How we perceive response times
9. So yes, our attention span is shorter than a goldfish
https://www.flickr.com/photos/watts_photos/23124797946
13. Most people don’t have an iPhone
% sales by OS, three months to April ’17 - http://uk.kantar.com/tech/mobile/
0
10
20
30
40
50
60
70
Android iOS Windows Other
24. Cook reduced load times by 1 sec saw 7% increase in conversions
https://www.nccgroup.trust/uk/about-us/newsroom-and-events/blogs/2017/march/how-we-predicted-an-increase-in-conversions-from-a-decrease-in-load-times
27. “Case studies don’t represent our
demographic, our audience, our
products, our proposition…”
Has some truth
28. BounceRate
0%
25%
50%
75%
100%
Page Load Time (s)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Site 1
Site 2
Site 3
Bounce rates across three retailers
29. ConversionRate
0%
2.5%
5%
7.5%
10%
Page Load Time (s)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Site 1
Site 3
Site 4
Conversion rates vary between sites too
Noisy as few data
points at end of range
57. Experiment
- Change the performance of a page
- Measure how metrics change
(Same principles as AB / MV testing)
Can build negative experiments
too e.g make pages bigger
58. Measure Visitors Experience
- Use the data to predict how improvements will
change the metrics
- Improve performance
- Verify the result