Blake Commagere discusses A/B testing, explaining its importance, methodologies, and common pitfalls, emphasizing the need for businesses with users. He insists that user instincts often differ from actual user behavior, thus requiring constant testing to optimize product features and messaging effectively. The talk invites engagement and humor while providing practical advice on avoiding mistakes in A/B testing.

1. @commagereBlake Commagere
A/B Testing
Technically Split or Bucket Testing, but
nobody calls it that.

2. Blake Commagere @commagere
Who the hell am I?
It’s a fair question
●Started seven companies
oFive of those have been bought
●Raised over 12M Angel / VC
●I build viral things
oPlaxo
oCauses
oVampires
●I’m obsessed with human behavior
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3. Blake Commagere @commagere
My Fucking Talks
Analogies Rule
Dave McClure Blake Commagere
●Makes sailors blush with
his swearing
●Occasionally uses
hyperbole in his talks
●Is funny
●Makes Dave McClure
blush with his swearing
●The most egregious
abuse of hyperbole
●Thinks he’s funny
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4. Blake Commagere @commagere
This talk is for you.
Interrupt at any point.
Don’t be shy.
If it sucks and you never say
anything, I’m blaming you.
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5. Blake Commagere @commagere
What I’m covering
●What the hell is A/B testing?
●Why should you care?
●How should you A/B test?
●How can A/B testing fuck you over?
●A few ancillary benefits of A/B testing
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6. Blake Commagere @commagere
What I’m NOT covering
AKA “Shit you should Google if you don’t already know”
●Familiarize yourself with concepts like
oConfidence Intervals
oComparative Error
oStatistical Significance
oSample Size requirements
 FYI, there are online calculators for all these things
●How to fucking do math
oYes there’s a lot of math in A/B Testing
oChances are, the tools you use will do the math for you
 If not, your code better do the math for you
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7. Blake Commagere @commagere
What the hell is A/B testing?
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8. Blake Commagere @commagere
What the hell is A/B Testing?
Will it hurt?
●Randomized Experiment
oControl & Variant
oTests against a specific goal
oTypically you want to establish Statistical Significance
with a Confidence Level of 95%
●Bucket or Split Testing
oTechnically, this is what you want most of the time
oMultiple variants
oPeople usually say A/B when they mean Bucket/Split
oJust go with it
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9. Blake Commagere @commagere
Why should you care?
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10. Blake Commagere @commagere
Do I really need A/B Testing?
Technically, you may not need it
●Do you have users?
●If not, do you plan on having users?
●If not… congrats! You don’t need A/B Testing
because you don’t have a business!
●For everyone else, you need A/B Testing.
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11. Blake Commagere @commagere
You are not your user
Your users are much, much stupider
You Your User
●Busy as hell
●Dedicated
●Very knowledgeable
●Eager to learn
●Not Stupid
●Lazy
●Impatient
●Stupid
●Stupid
●Real. Stupid.
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12. Blake Commagere @commagere
The Result?
You’re building the product for you
●You are not your user
●Your instincts are probably wrong
●Your wants/needs are probably different
●You view the market differently
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13. Blake Commagere @commagere
Still not convinced?
●Create and Make are synonyms
●“Make an Ad” vs “Create an Ad”
●Software Prefers ‘Create’ because REST, CRUD
●Make outperformed by up to 20% for non-artists
●There is a mental barrier to Create - it sounds
more involved/complex. Making is easier.
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Create vs Make - one word makes all the difference

14. Blake Commagere @commagere
How should you A/B Test
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15. Blake Commagere @commagere
Blockers on your A/B testing
If this is happening, all your tests will suck
●Shit is broken
oFIX IT NOW WHY ARE YOU FUCKING READING THIS
●Shit is slow
oPageSpeed on frontend,
oProfilers on backend / mobile
●Official definitions of slow*
oA webpage that takes > ~2 seconds & no progress indicator
oAn app that isn’t immediately responsive
*according to me
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16. Blake Commagere @commagere
Ensuring tests maximize impact
AKA the most obvious advice ever
1)ABT. Always Be Testing
2)Win as frequently as possible
3)In areas that matter
●Any moron can get #1 right
●Most morons can’t do #2 or #3
●Essentially, you need to know what to test and
how to test.
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17. Blake Commagere @commagere
Only a few features matter
That’s it
●Users are either engaged or not
●Data on your userbase tells you which 2-3 features
matter
●Optimize these features
●Make Onboarding focus on these features
●Facebook example:
oFriends, Photos, Status Updates
oNew User Experience focused on these
oNetwork leverage to help new users
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18. Blake Commagere @commagere
Similarly, only a few flows matter
●Is a flow critical?
odoes it get a user engaged with a critical feature
odoes it help another user engage with a critical feature
●Is every step necessary?
oAlmost always, the answer is no
●Where are the leaks?
oAlmost always, this is the result of bad messaging
oFind the worst leak, fix it, then move to the next one
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That’s also it

19. Blake Commagere @commagere
Your messaging is never perfect
AKA test your fucking messaging
●In most cases it is better to:
oUse fewer words - your users are lazy
oBe Colloquial - your users are dumb
oTarget the user - your users are selfish
●You can always target better
oSome data is implicit to your existing data
oYour users only care about what they get
●Language is always evolving
oLanguage in every channel is evolving as well
oChannels change & language in a channel changes!
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20. Blake Commagere @commagere
Tools of the trade
●Web:
oGoogle Analytics (Content Experiments)
oOptimizely
oMixPanel
●Mobile:
oMixPanel
oOptimizely
oSwrve
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21. Blake Commagere @commagere
Which tool should I use?
●The best one for your company:
oIt depends
oOn. so. many. things.
●You’ll end up doing some coding too probably.
●The worst one for your company?
oNot having one
oCreating your own from scratch
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22. Blake Commagere @commagere
How A/B Testing can fuck you over
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23. Blake Commagere @commagere
Pitfalls
Some very common mistakes
●Find statistical significance sample size in advance
oYou want 95% confidence level
oWith 20,000 users, this can be 377 people. NOT
50/50
●Do not take convenience samples
o2-4 weeks is ideal
●Test in 7, 14, 28 day intervals
oHuman behavior is day dependent, tied to week
oYour results will skew if you do 8 day tests
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24. Blake Commagere @commagere
The Lies We Tell Ourselves
Sometimes we like lying because we’re lazy
●You can make the numbers lie
●Avoiding a channel that you hate
oEmail works
oSEO works
oTwitter works
oFacebook works
oIf a channel doesn’t work for you,
you’re probably doing it wrong
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25. Blake Commagere @commagere
Farmville
How to optimize for suck
Farmville on Launch Farmville after ~2 yrs
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26. Blake Commagere @commagere
Ancillary Benefits
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27. Blake Commagere @commagere
Designer vs Engineer
Your users are much, much stupider
Designer Engineer
●Better not suck at design
●Better have design exp
●Better respect design
●Will not always agree with
engineers on design
●Not Stupid
●Probably sucks at design
●May not have design exp
●Should respect design
●Will not always agree
with designers on design
●Not Stupid
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28. Blake Commagere @commagere
Using A/B Testing for Team Bonding
●The loudest voice usually gets their way
●This can stifle good ideas
●Sometimes it’s ok to test a bad idea
●Becomes a teachable moment
●You could be wrong (GASP!)
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29. Blake Commagere @commagere
Want more swearing and/or advice?
blake.commagere@gmail.com
@commagere
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