Company overview:
Box2box is an online market palace where customers can order anything where ever they are around the globe and get them delivered to their doorstep.

Business context:

The E-commerce brand wants to increase checkout conversions and increase revenue.
Will changing the Add to Cart button color from blue (current) to green (variant) increase conversions?

Why does this matter? Well, More conversions = More revenue.

Hypotheses:
Changing the add to cart button from BLUE to GREEN will increase purchases by 10% among new visitors over 14 days because warm color is louder, increases awareness, improves readability and CTA salience

Statistical Analysis/Decision rule
Experiment : A/B TEST

Method: Two-proportion z-test

Null Hypothesis (H₀): No difference in conversion.

Decision: Reject H₀ → If Green button significantly outperforms Blue.

Null (H₀): CRₐ = CRᵦ (no difference).
Alternative (H₁): CRᵦ > CRₐ (green button improves conversion).

Ship variant (green button) if primary metric’s 95% cl excludes 0 and guardrails shows no harm

CRₐ - blue button
CRᵦ - green button

Experimental Design

Population: Website visitors.
Sample: Split traffic 50/50 into Group A (blue button) and Group B (green button).

Metrics:

Primary: Conversion rate (purchases ÷ visitors)
Secondary: Add-to-cart clicks, bounce rate.
Duration: 2 weeks

3. Data Collection

Groups
Group Visitors (n)
Purchases (x)
Conversion Rate (CR = x/n)

PROJECT WORKTHROUGH
We tested if a button color change could increase sales.

Table of visitors & conversions.

A (Blue) 5,000 500 10%
B (Green) 5,000 624 12%

SUMMARY OF FINDINGS
We ran a z-test to check if the uplift was real or just a random chance.

Results
Z-stats = -3.926
p -value = 0.0001
Observed lift = 2% (CRᵦ-CRₐ)
Relative lift = 20% (CRᵦ-CRₐ)/CRₐ*100
95% ci = (+1.24%, +3.72%)

What it means…….

P value(0.0001)< 0.05 means that the result is statistically significant and the result is not likely due to chance or random.

An observed lift of 2% shows that there is a clear increase in conversion (+76 more conversions)

A relative lift of 20% shows that the variant (green button) improves conversion relative to control (blue button , our current color)

95% ci excludes zero, this result increases our confidence in the results of this experiment and gives assurance that we will see increased revenue and conversions if we switch to the green button color .

In summary, The green button increased conversions by 20% relative lift, p < 0.05.

Business Impact

Absolute lift: +2% (10% → 12%)

Relative lift: +20%

Projected impact:

With 100,000 monthly visitors → +2,000 conversions

Avg order value = $50 → +$100,000/month

With a 20% (an extra 2,000 conversion) increase in conversion from our average 100,000 monthly visitors and an average order value of $50, we are likely to make an increased revenue of $100,000 per month, if we change our add to cart button colour from blue to green.

Insight
The green button improves conversions significantly.

Recommendation
Roll out the green button asap.

Next step:
Test button placement or wording for further lift.