A/B testing helps improve websites and apps by comparing two versions to see which performs better. This checklist covers key steps to ensure your tests are set up correctly:
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Set clear goals and hypotheses
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Plan your test carefully
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Set up technical tools and tracking
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Analyze traffic and sample size needs
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Choose metrics and statistical thresholds
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Check user experience across devices
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Determine optimal test timing and length
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Perform quality checks on all versions
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Review legal and ethical considerations
Step | Purpose |
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Goal setting | Focus on what matters |
Test planning | Design solid experiments |
Technical setup | Configure tools properly |
Traffic analysis | Ensure statistical significance |
UX checks | Provide smooth user experience |
QA | Catch errors early |
Legal review | Stay compliant and ethical |
Use this checklist to avoid common A/B testing pitfalls and get reliable results to improve your site or app. Proper setup leads to actionable insights and better business decisions.
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How to Use This Checklist
This 15-point checklist is your A/B testing roadmap. Here's how to use it:
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Read it all first. Get the big picture.
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Apply each point. Don't skip steps.
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Track your progress. Note what's done and what's next.
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Share with your team. Keep everyone in sync.
It covers these key areas:
Topic | Purpose |
---|---|
Goal Setting | Focus on what matters |
Test Planning | Design solid tests |
Technical Setup | Get tools and tracking right |
Traffic Analysis | Reach statistical significance |
User Experience | Ensure smooth testing |
Quality Assurance | Catch errors early |
Legal Compliance | Stay ethical and lawful |
Each section has specific actions. For goals, you'll learn to write clear hypotheses and set measurable targets.
Remember, A/B testing is about learning. As Noel Griffith, CMO at SupplyGem, says:
"The number one tip for A/B testing in marketing is to clearly define your goals and metrics before conducting any tests."
This checklist guides you from start to finish, setting up your A/B tests for success.
Setting Clear Goals
A/B testing without clear goals is like sailing without a compass. You need specific, measurable objectives that align with your business needs.
Writing a Clear Hypothesis
A strong hypothesis is key. Use this structure:
"If {I do this}, then {this will happen}."
For example:
"If I add 'Free shipping' as a USP, then visitors will buy more items."
This hypothesis is clear, specific, and measurable. It gives your test direction.
To craft a solid hypothesis:
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Identify the problem
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Propose a solution based on data
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Predict the outcome
Back your hypothesis with evidence from:
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Website analytics
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Customer surveys
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Heatmaps
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Previous test results
Setting Measurable Goals
Your goals should support your business objectives:
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Identify main business objectives
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Choose A/B testing goals that support them
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Select KPIs to measure success
For an eCommerce site:
Business Objective | A/B Testing Goal | Primary KPI |
---|---|---|
Increase revenue | Boost product page conversions | Average order value |
Reduce cart abandonment | Improve checkout process | Cart abandonment rate |
Set a primary KPI for each test as your main success indicator.
Michael Aagaard, a conversion copywriter, shares:
"By changing the CTA copy from 'Start your 30 day free trial' to 'Start my 30-day free trial,' we saw a 90% increase in sign-ups."
This small change, based on a clear hypothesis about personal pronouns, led to a big win.
When setting goals and writing your hypothesis:
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Be specific about what you're testing
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Ensure your goals are measurable with your tools
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Allow for a range of acceptable outcomes
Planning Your Test
A/B testing isn't about random changes. It's about smart, data-driven decisions. Here's how to plan effectively:
Control vs. Test Groups
Splitting your audience right is crucial. Here's the breakdown:
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Control group: Your current version. It's your benchmark.
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Test group: The new version you're testing.
Both groups should be similar in size and makeup. For a homepage test, you might split traffic 50/50 between old and new designs.
Group | Purpose | Example |
---|---|---|
Control | Benchmark | Current homepage |
Test | New version | Updated homepage |
Your control group is just as key as your test group. Without it, you can't measure impact.
Limiting Changes
Want clear results? Focus on one change at a time. Here's why:
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Single element tests: Pinpoint what's driving results.
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Multi-element tests: Use sparingly, with good reason.
Airbnb once tested different button label wording. This narrow focus showed the impact of that specific change.
But what if you need bigger changes? Consider:
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Traffic levels: High-traffic sites can test small changes. Low-traffic sites might need larger changes for quick results.
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Page importance: Critical pages might need multiple changes to address several issues.
Matt Gershoff, CEO of Conductrics, says:
"If you don't care about the marginal effect of any sub-component/dimension of your change, then go ahead and just compare the mega-state/combo effect."
Sometimes big changes are okay. Just have a clear reason.
Remember: The goal is to boost revenue, not just run tests. Plan with that in mind.
Technical Setup
Setting up your A/B test right is crucial. Here's how:
Choosing and Setting Up Testing Tools
With Google Optimize going away, you need a new A/B testing tool. Here's what to do:
1. Pick a tool
Look at ease of use, integrations, and price. Convert, for example, costs $99/month and has great support.
2. Set it up
Sign up and follow their instructions. Add their tracking code to your site's <head>
tag. Then create your test in their interface.
Here's a quick comparison of some tools:
Tool | Good for | Standout Feature |
---|---|---|
Captchify | Small/medium businesses | A/B/n Testing and Metrics Analysis |
Kameleoon | Big companies | AI insights |
VWO | All-in-one | Heatmaps & recordings |
Adding Tracking Codes
Good tracking = accurate data. Here's how:
1. Use Google Tag Manager (GTM)
GTM makes code management easier:
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Make a GTM account
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Add GTM code to your site
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Set up variables for your test versions
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Create triggers for each version
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Make tags to track events
2. Set up Analytics
Create goals in Google Analytics to measure your results.
3. Test it
Use GTM's preview mode to check everything works before going live.
"Kameleoon gives marketers, developers, and product managers a powerful tool to build impactful customer experience optimization programs." - Ben Labay, Speero's Managing Director
Traffic and Sample Size
Getting your A/B test's traffic and sample size right is crucial. Here's what you need to know:
Estimating Website Traffic
First, check your site's traffic:
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Look at monthly visitor numbers
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Check daily patterns
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Think about seasonal changes
Got 30,000 visitors a month? That's roughly 1,000 per day. But watch out - weekends might be slower.
Calculating Sample Size
Your sample size depends on:
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Baseline conversion rate (BCR)
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Minimum detectable effect (MDE)
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Statistical significance
Let's say your signup page converts at 20%. You want to spot a 2% increase. That's an MDE of 10% (2% / 20%).
Here's a quick guide:
Monthly Visitors | Minimum Improvement Needed |
---|---|
< 10,000 | > 30% |
10,000 - 100,000 | 9% - 30% |
100,000 - 1M | 2% - 9% |
> 1M | < 2% |
For solid results, aim for:
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1,000+ contacts per variation
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100+ conversions per version
Pro tip: Use a sample size calculator. Input your BCR, MDE, and confidence level (usually 95%). It'll tell you how many visitors you need.
In our signup page example, you'd need about 5,400 visitors total (2,700 per variation) to spot that 2% increase with 95% confidence.
More variations? You'll need more traffic. Stick to A/B tests unless you've got TONS of visitors.
"Low traffic? Focus on top-of-funnel conversions or limit your test variants." - A/B Testing Best Practices Guide
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Data Collection and Analysis
A/B testing success hinges on smart data collection and analysis. Here's the lowdown:
Choosing Key Metrics
Pick metrics that align with your test goals:
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Conversion rate: (Conversions / Total visitors) x 100
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Click-through rate (CTR): (Clicks / Impressions) x 100
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Bounce rate: % of single-page visits
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Average order value (AOV): Total revenue / Total orders
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Revenue: Number of orders x AOV
Focus on 1-2 primary metrics for your main goal. Add 2-3 secondary metrics for extra insights.
Metric Type | Examples | Purpose |
---|---|---|
Primary | Conversion rate, Revenue | Measure test outcome directly |
Secondary | Bounce rate, Time on page | Provide supporting data |
Setting Statistical Thresholds
To avoid false positives:
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Set confidence level (usually 95%)
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Choose minimum detectable effect (MDE)
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Calculate required sample size
Confidence Level | P-value | Interpretation |
---|---|---|
95% | 0.05 | 5% chance of false positive |
99% | 0.01 | 1% chance of false positive |
Some tips:
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Run tests for at least 7 days or a full business cycle
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Aim for 1,000+ visitors and 100+ conversions per variation
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Use a sample size calculator for test duration
"If the loss rate is normal, businesses should learn from lost tests, recognizing that loss is part of A/B testing and can sometimes be more valuable than wins." - Anwar Aly, Conversion Specialist at Invesp
Don't jump the gun. Let tests run their full course for accurate data. Patience pays off in A/B testing.
User Experience Checks
A/B testing isn't just about numbers. It's about making sure your users have a smooth experience. Let's look at two key areas:
Mobile Device Testing
More people are browsing on their phones. So, mobile testing is a must. Here's what to do:
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Use mobile-friendly A/B testing tools
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Test on different devices
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Check load times (aim for under 3 seconds)
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Make sure touchscreen interactions work well
Mobile Test | Why It's Important |
---|---|
Responsive design | Fits all screens |
Touch-friendly elements | Easy to use on mobile |
Fast load times | Keeps users on your site |
Readable text | Easy to read on small screens |
Browser Compatibility
Different browsers can show your site differently. Here's how to handle this:
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Make a Browser Matrix
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Use analytics to see what browsers your users prefer
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Test on both new and older browsers
Browser Type | What It Means | Examples |
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New | Works great, common | Chrome, Firefox, Safari |
Older | Less capable | IE 8, 9 |
Rare | Basic support only | Unknown browsers |
"Test your website on different devices at least a week before launch." - MECLABS Institute
Good testing can find surprising issues. WallMonkeys, an e-commerce company, saw their conversion rate jump 550% after improving their app through A/B testing.
Test Timing and Length
Picking the right timing and length for your A/B test is key. Here's what you need to know:
Deciding Test Length
Many A/B tests fail because they're too short. To avoid this:
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Run for at least 2 weeks
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Aim for 95% confidence level
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Cover full business cycles (1-2 weeks)
Duration | Pros | Cons |
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1 week | Fast results | Misses weekly patterns |
2 weeks | Captures weekly cycles | Might lack confidence |
4+ weeks | High confidence | Slower implementation |
"Sequential testing lets you deploy winners early and stop unlikely tests fast." - Georgi Georgiev, Statistician and Author
Considering Seasonal Factors
Seasons can skew your results. Here's how to handle them:
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Spot seasonal patterns in your data
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Increase sample size for full seasonal cycles
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Skip high-traffic events like Black Friday
Season | What to Watch For |
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Holiday | More traffic, different intent |
Summer | Possible B2B traffic dip |
Back-to-school | Interest in certain products |
Quality Checks
Before launching your A/B test, run these quality checks. They'll help you avoid mistakes and keep your test results reliable.
Testing All Versions
Test each version of your experiment before you start:
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Click all links and buttons
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Make sure images load
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Go through the whole funnel, not just the test page
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Use BrowserStack to check different browsers
Here's a quick checklist:
Check | What to Look For |
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Links | Work and go to right pages |
Images | Load correctly |
Tracking | Google Analytics code is there |
Goals | Set up in Google Analytics |
Mobile | Looks good on phones and tablets |
Avoiding Conflicts
Your A/B test shouldn't mess up other parts of your site. Here's how to keep things running smoothly:
1. Run an A/A test first
This helps you spot issues early. As A/B Testing Expert Ronny Kohavi says:
"To ensure trustworthy test results, you need to know how to properly interpret p-values."
An A/A test can catch bugs before they become problems.
2. Check for other tests
Make sure your new test won't clash with tests already running.
3. Watch your site speed
Some A/B testing tools can slow down your site. Use Google's speed test tool to check. Slow pages can lead to fewer conversions.
4. Look for Sample Ratio Mismatch (SRM)
SRM can mess up your results. Use an A/B testing tool that can spot SRM early.
Legal and Ethical Checks
Before you start A/B testing, make sure you're not breaking any laws or crossing ethical lines. Here's what you need to do:
Privacy Policy Review
1. Check your privacy policy
Does it cover A/B testing? If not, update it. Your policy should clearly state:
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What data you're collecting
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How you're using it
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How long you're keeping it
2. Follow privacy laws
Different regions have different rules:
Law | Region | Key Points |
---|---|---|
GDPR | EU | User consent required, right to be forgotten |
CCPA | California, USA | Users can opt-out, right to know collected data |
BDSG | Germany | Strict data processing and storage rules |
3. Use compliant tools
Choose A/B testing tools that follow these laws. Look for:
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Data Protection Impact Assessment (DPIA)
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Data anonymization features
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"Do Not Track" respect options
User Consent
Getting user consent isn't just polite - it's often legally required. Here's how:
1. Be upfront
Tell users you're A/B testing. A simple message on your landing page works.
2. Explain the test
Let users know what you're testing, why, and how you'll use their data.
3. Easy opt-out
Make it simple for users to say no to A/B tests.
4. Monitor consent rates
If less than 50-60% of users agree, rethink your approach.
"It's not acceptable to me to manipulate people's emotion. That is not acceptable without informed consent." - Ehud Reiter, Professor of Computing Science at the University of Aberdeen
Don't test without consent. In 2014, Facebook tested 700,000 users without telling them. The backlash was huge.
Conclusion
A/B testing is your secret weapon for making smart choices and boosting your website. But it's not just about running tests - it's about doing them right.
Here's what you need to know:
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Set clear goals
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Plan carefully
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Get the tech right
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Have enough traffic
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Analyze smartly
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Check user experience
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Time it well
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Quality control
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Stay legal and ethical
Why bother with all this prep? It helps you avoid mistakes, save time, get better data, and make smarter decisions.
"Our success at Amazon is a function of the number of experiments we run per year, per month, per day." - Jeff Bezos, Amazon founder
Amazon's not the only one crushing it with A/B tests. Airbnb made millions just by opening listings in a new tab. Netflix keeps users hooked with personalized homepages.
Company | Test Change | Result |
---|---|---|
Amazon | Tons of tests | Keeps growing |
Airbnb | New tab for listings | $$ |
Netflix | Personal homepages | Users stick around |
Here's the deal: Every A/B test teaches you something. Win or lose, you're learning about your users and your product.
So use this checklist. Run your tests. And keep learning. That's how you'll win in the digital game.
FAQs
What precautions should you take when designing a B test?
When setting up a B test, focus on what matters:
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Test pages that get lots of traffic and are part of your sales funnel
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Pick important stuff like product pages or checkout steps
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Change just one or two things per test
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Make sure you have enough visitors for your results to mean something
How to validate a product before launch?
Here are some quick ways to check if your product idea has legs:
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Try to make some pre-sales
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Look for existing demand
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Ask people to fill out a survey
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Start a crowdfunding campaign
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See what social media thinks
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Build a simple landing page
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Talk to potential customers face-to-face
How do you set up an A/B test?
Here's how to get an A/B test going:
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Check how your website's doing now
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Come up with a clear guess (like "If we change X, Y will happen")
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Make different versions to test
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Run the test
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Look at the results and make changes
What is the A/B testing strategy?
A/B testing is like a marketing experiment where you:
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Split your audience in two
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Show each half a different version of your stuff
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See which one does better
It helps you make smart choices about your marketing, website, and how users interact with your stuff.
"Testing is the crucible for decision making." - Chris Goward, Marketing Expert