AOV (average order value)

AOV is total revenue divided by order count, and it is the number the rest of ecommerce unit economics is built on. Breakeven CPA is AOV multiplied by contribution margin. Budget planning runs revenue goal divided by AOV to get the orders required, then divides by conversion rate to get the clicks. Move AOV and every one of those figures moves with it.

This is why raising AOV is among the most efficient advertising work available, even though none of it happens inside an ad account. Take a store at $80 AOV and 40% margin: breakeven CPA is $32. Lift AOV to $92 through bundling, a free-shipping threshold, or a post-purchase upsell, and breakeven CPA becomes $36.80 at the same margin — a 15% wider allowable cost per order. That extra headroom does not just improve reported efficiency. It makes previously unaffordable audiences affordable, which is how accounts find new volume without new creative.

The same lift compounds on the budget side. A $200,000 revenue month needs 2,500 orders at $80 AOV, and 2,174 at $92. Fewer orders for identical revenue means less traffic, less spend, and less pressure on every bidding constraint at once.

The mistake is trusting the mean. AOV is an average over a distribution that is often bimodal, and an average sitting between two modes describes neither of them. A catalog with a $30 accessories cluster and a $400 hero-product cluster might report a $95 AOV that essentially no order resembles. Setting one breakeven CPA from it prices the accessories traffic generously and the hero traffic far too tightly, so the campaign that deserves the most budget is the one held to the strictest target.

Look at the distribution before setting anything from the mean. If order values cluster into distinct groups, separate the campaigns that serve them and give each its own AOV and its own targets. Where the distribution is genuinely unimodal, the average is safe to use.

Two further cautions. Compute AOV on the same revenue basis as everything else — net of discounts and returns, or gross, but consistently, because a gross AOV paired with net margin quietly inflates allowable cost. And watch AOV alongside conversion rate: a threshold that lifts AOV while suppressing conversion can leave total contribution flat or lower, which the AOV figure alone will present as a win. The number worth protecting is contribution per session, since that is what both levers ultimately move.