AOV (Average Order Value)

E-commerce indicator that represents the average value of a purchase made by a customer. It is calculated by dividing total revenue by the number of orders over a given period:
AOV = Total revenue ÷ Number of orders

Example:

If a site generates €10,000 in revenue from 200 orders, the AOV is €50.

In an A/B testing context:

AOV is often used to measure the impact of a variation on the value generated per order (e.g., testing a cross-sell module, a new promotion, or an upsell at checkout).

However, AOV is a continuous variable sensitive to extreme values (e.g., a few very large carts can inflate the average). This makes it statistically unstable for classic A/B tests based on averages (such as Student's t-tests).
➡️ It is therefore recommended to use a non-parametric test such as the Mann-Whitney U test, which is more robust against outliers.

CRO recommendation:

It is not recommended to use AOV directly as the main KPI for validating an A/B test, as its distribution is rarely normal.
👉 A more reliable alternative is to transform the KPI into a binary rate, for example:

• % of sessions with a cart addition above €X
• % of sessions with at least one premium-range product
• Conversion rate of a specific cross-sell

These metrics are more stable, compatible with classic A/B tests, and more directly actionable for guiding optimization decisions.