Velocity Santa Clara 2016 talk! Users’ ad blockers are impacting your site’s perceived performance, but measuring the impact of ad blockers on actual and perceived performance can be difficult. While ad blockers are reported to improve performance, the lack of proper tooling can make metrics difficult to collect and their true impact difficult to measure. Karan Kumar offers an overview of new testing he has created that measures the overall impact ad blockers have on the quality of user experience and performance across a number of sites. Topics include: How ad blockers work The components of these extensions that cause the biggest impact on performance Issues that arise in terms of user experience The impact of ad blockers on top Alexa and Internet retailer sites How to create a private instance to measure the impact of ad blockers on your own website with open source technology Link to description http://conferences.oreilly.com/velocity/devops-web-performance-ca/public/schedule/detail/51264

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Karan Kumar
Technical Lead Performance Engineering
June 23, 2016
Measuring Ad Blocker’s
impact on
Site Performance

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Web Performance
Devices
Format/capability diversity
Sophisticated Apps
Visual, personalized, complex
Networks
0
50
100
150
200
250
Wired LTE WiFi 4G 3G
Latency(ms)

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Popular browser extensions
> 500 million downloads
> 200M + active users
100M + active users
Adblock Plus blog, 9th May 2016
http://i.imgur.com/IG8oVar.png
https://chrome.google.com/webstore/category/popular

4. 44Source: https://downloads.pagefair.com/wp-content/uploads/2016/05/2015_report-the_cost_of_ad_blocking.pdf

5. 55Source: https://downloads.pagefair.com/wp-content/uploads/2016/05/2015_report-the_cost_of_ad_blocking.pdf

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BROWSER = EXTENSION =

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Bird's-eye view
Content
Ads
Filter lists
Source: http://adforads.com/category_images/website.jpg
https://www.digitalmusicnews.com/wp-content/uploads/2015/11/adblocklogo.png
http://findicons.com/files/icons/1579/devine/256/list.png

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Performance Impact ?

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Performance Impact
Source: https://twitter.com/inspiredlabs/status/743037699561492480

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Performance Impact
Source: https://twitter.com/WalterStephanie/status/742979562049548289

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“”The results: For a number of websites
that contained mobile ads with a lot of
data, web page data sizes decreased
significantly and load times accelerated
enormously with ad blockers turned on.””
NY Times Oct 1st 2015
Performance Impact
Source: http://www.nytimes.com/2015/10/01/technology/personaltech/ad-blockers-mobile-iphone-browsers.html?_r=1

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Performance Impact
Source: http://rigor.com/blog/2016/06/ad-blocking-above-all-else
“Above All Else, Ad Blocking is a User Experience Problem”
Rigor: 21th June 2016

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Extend WebPagetest
• Easy to extend WebPagetest
 Detailed Step-by-Step instructions
• Side-by-Side comparison
• Multivariate tests

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Experimental Setup
• Private WebPagetest instance
• WebPagetest replay
 Record live website and playback
 Reduce outliers (time of day, network, DNS, server load etc.)
 Normalize the results
• Cable connection
• Chrome 51 Browser on Windows
Vs.

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 1: moviemistakes.com

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Example 2: apple.com

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Example 2: apple.com
No requests were blocked

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Example 2: apple.com

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Example 2: apple.com

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Example 2: apple.com

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Example 2: apple.com

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Example 3: parents.fr

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Example 3: parents.fr

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Example 3: parents.fr

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Example 3: parents.fr

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Example 3: parents.fr

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Example 3: parents.fr

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Example 3: parents.fr

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Example 4: etsy.com

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Example 4: etsy.com

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Example 4: etsy.com

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Example 4: etsy.com

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Example 4: etsy.com

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Example 4: etsy.com

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Example 4: etsy.com

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Summary of examples
• Moviemistakes.com
 Better Speed Index, Start Render
• Parents.fr
 Better Speed Index, Worse Start Render
• Apple.com
 Worse Speed Index, Start Render
• Etsy.com
 Worse Speed Index, Start Render
• Higher Time To First Byte

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More Experiments
• 2016 Internet Retailer 150 Homepages
• 2016 Top 100 Media Sites

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2016 Internet Retailer 150 Homepages

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2016 Top 100 Media Sites

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Observations
• CPU cycles for blocking content
• Varies by industry
• Huge filter list
 Blocked list
• 580 KB (~1.9 MB)
 Allowed list
• 422 KB (~1.9 MB)
• User experience could be worse

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Takeaways
 Overheads of Ad blocker's
 Benefit from blocking content
 performance != universal
 Invest in tooling
 Measure it

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Thank You!
www.instartlogic.com
Karan Kumar
kkumar@instartlogic.com
@kkumar86
https://www.linkedin.com/in/kkumar86
BOOTH @ 215

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View Blocked Content
Without Adblocker Adblocker