most of your customers buy one thing - that's where the money is
here's a number from a real audit. orders with two or more items in them were worth 2.4 times a single-item order. that part isn't surprising - more stuff in the basket, bigger order. the surprising part: fewer than 1 in 5 baskets had more than one thing in them.
read that again. four out of five customers bought one item and left. the store had already done the hard, expensive work - found the customer, earned the click, won the sale. and then said nothing about the second thing that customer almost certainly wanted.
that gap is the cheapest revenue in ecommerce. you're not paying to acquire anyone. you're not rebuilding anything. you're talking to people who are already buying, at the exact moment they've decided to trust you with their card.
most stores leave it on the table for one of three reasons. the product pages don't suggest what goes with what. the cart doesn't nudge. or - most common - nobody's ever looked at the basket data closely enough to know which products actually get bought together, so the cross-sells are guesses.
that last one matters. "customers also bought" widgets are usually generic, pulling whatever's popular rather than what genuinely pairs. the pairs that convert are hiding in your order history. you already own the answer.
the fix isn't a campaign. it's reading your own line-item data, finding the real pairs, and putting them in front of people at the right moment - product page, cart, post-purchase. small changes, measured against a number you can actually see move.
this is the first thing we look at in an audit, because it's usually the fastest win. what's your single-item order share? if you don't know, that's the first thing worth finding out.