Ecommerce · 3 min
Five cross-sells and no checkout button: When the cart tries too hard
An interactive case study: a candle shop's cart shows five cross-sell carousels that push checkout off screen. The team tests one relevant suggestion.
Learn CRO for free, one small lesson at a time
A practical conversion rate optimization course for beginners and busy marketers. Short, visual lessons, interactive case studies and free A/B testing tools show you why visitors leave and how to fix it.
- 64 short lessons
- No sign-up, ever
- Reviewed by a CRO expert
The short answer
What is conversion rate optimization (CRO)?
Conversion rate optimization (CRO) is the practice of finding out why visitors don’t take the action you want, such as buying, signing up or booking a call, and then testing changes that remove those reasons. Your conversion rate is the share of visitors who complete that action: conversions divided by visitors.
Good CRO is not button colours or “best practice” lists. It is research first (analytics, recordings, surveys, user tests), then a clear hypothesis, then an A/B test or a careful rollout, then learning you can reuse. That is exactly the order this free CRO course teaches it in.
- Research: find where and why people drop off
- Hypothesis: one change, one reason, one metric
- A/B testing: let real visitors decide
- Analysis: read results honestly, including the flat ones
- Rollout: ship what works and share the learning
What you’ll learn
From “why is nobody buying?” to “here’s what we’ll test next”
Spot where visitors leave
Read a funnel and find the step that loses the most people.
Understand why they hesitate
Use surveys, recordings and psychology to find the real reason.
Test ideas without guessing
Run A/B tests you can trust, even if you hate statistics.
Explain results so people care
Turn a test into a story your boss and clients actually read.
How CRO works
It’s a loop, not a magic trick
Look
Watch what real visitors do before changing anything.
Guess smart
Turn what you saw into an idea worth testing.
Test
Show the idea to half your visitors and compare.
Keep what works
Roll out the winners, learn from the rest, repeat.
In the course you’ll meet this loop by its full name in lesson 7. For now, four words are enough.
The free course
8 modules. 64 lessons. Zero to confident.
Module 1
Foundations
What CRO is, what it isn't, and how to measure what actually matters.
Module 2
Research
How to find out why visitors hesitate, without guessing.
Module 3
Analytics
Read your numbers with confidence, and spot the step where people leave.
Module 4
Strategy
Turn what you found into ideas worth testing, in the right order.
Module 5
Experiment science
The statistics behind A/B tests, without the scary bits.
Module 6
Implementation
Build, check and launch tests that don’t break anything.
Module 7
Applied CRO
Apply it all to landing pages, online stores and SaaS products.
Module 8
Practitioner practice
Put it together on a practice business and earn your certificate.
Case studies
Click through real problems, slide by slide
Ecommerce · 3 min
The filters nobody found: Helping mobile shoppers narrow 400 products
An interactive case study: a running shop hides mobile filters behind an unlabelled icon. The team tests visible filter chips and measures orders.
Ecommerce · 3 min
The shipping-cost surprise: Why shoppers bail at checkout
An interactive case study: how a plant shop finds a late shipping-cost surprise, scores a fix with PXL, plans an A/B test and rolls out the learning with WXM.
Free tools
Answers to the three questions everyone asks
How long should my test run?
Sample size and duration in seconds, with the maths shown.
Open the calculatorWhich idea should I test first?
Score your test ideas and get a ranked list you can export.
Rank my ideasWhat is wrong with my page?
A free audit checklist. Tick it in your browser, no sign-up.
Run the checklist
Psychology
Why people click, hesitate and buy
Psychology · 2 min
Anchoring
Anchoring is the tendency for estimates and judgments to lean towards the first number people see, even an irrelevant one.
Psychology · 2 min
Choice overload
Choice overload is the idea that too many options can make people choose less or feel worse about their choice.
Psychology · 2 min
Decoy effect
The decoy effect is when adding an option that's clearly worse than one alternative makes that alternative more popular.
Psychology · 2 min
Framing effect
Framing is how the same information is described: as a gain or a loss, as a percentage or a number, per day or per year.
Psychology · 1 min
Loss aversion
Loss aversion is the finding that losses can weigh more than equal gains in decisions.
Psychology · 2 min
Social proof
People look to what similar others do, especially when they're unsure.
Learn CRO by topic
Pick the CRO question you have today
CRO basics
Research and strategy
A/B testing and statistics
CRO by page and business
Templates and tools
Who it’s for
CRO for beginners, and for the people who already do the work
Complete beginners
Never heard of CRO? Lesson 1 starts at zero and builds one idea at a time.
Marketers and growth teams
Turn traffic you already pay for into more leads, signups and sales.
Ecommerce and SaaS owners
Find the leaks in product pages, checkout, trials and onboarding.
Designers, developers and analysts
Learn the research, testing and statistics side so your work gets measured fairly.
Prefer a human?
Want someone to do it with you?
Learning here stays free. If you’d rather have senior CRO people on your funnel, your test backlog or your team, our partner team can help.
Questions people ask first
How do I learn CRO from scratch?
Start with how conversion rate is measured and why visitors drop off, then learn research methods, writing hypotheses, A/B testing and basic statistics, in that order. The free Mentorele course follows exactly that path in 64 short lessons, with case studies to practise on.
Is Mentorele really free?
Yes. Every lesson, case study, template and calculator is free to read. No account, no email gate. Paid help (consulting, mentoring, team training) is optional.
I have never done CRO. Can I start here?
That is exactly who lesson 1 is for. It starts at "what is CRO?" and builds up one small idea at a time. No maths needed until module 5, and we explain it when we get there.
Who writes the lessons?
Phil the CRO Guy, our guide, presents every lesson. Each one is checked by Filip Doneski, Lead CRO Strategist at Wavesy, with 10+ years in conversion optimization and experimentation.
Do I need paid tools to start with conversion rate optimization?
No. Free analytics, a free session recording tool and our free calculators are enough to learn and run your first research. A/B testing tools come later, and several have free plans. See our CRO tools guide for free options first.
How long does it take?
Most lessons take 5 to 10 minutes. Do one a day and you finish a module in about a week and a half.