Upselling and Cross-Selling.

The difference lies in direction. Upselling goes up: the larger package, the better model, the longer term. Someone buying a coffee machine is shown the model with a milk frother. Cross-selling goes sideways: something that goes with the purchase. A coffee machine pairs with descaler, beans or a service agreement. In online shops this appears as 'customers also bought' or accessories in the basket; in service businesses as an optional extra in the quote.

Commercially it is attractive because the most expensive work has already been done. The customer has built trust and made a buying decision, so no additional acquisition is needed, see customer acquisition cost. Every extra franc per customer raises customer lifetime value. In subscription models, expansion revenue from existing customers can offset losses from cancellations, see churn rate.

For it to work, the offer must genuinely benefit the customer. A relevant suggestion at the right moment feels like service; a pushy one feels like a sales trick. Good rules are: one or two suggestions at a time, clearly visible prices and nothing pre-selected that the customer has not actively chosen. Pre-ticked boxes and hidden extras are dark patterns and cost trust.

Success can be measured through average order value, the share of orders with an add-on and, for services, the share of quotes with an optional extra. Keep an eye on the downside too: if returns, cancellations or complaints rise, too much was sold. In a Shopify store, product recommendations and bundles can be set up with built-in features or apps; for services, a well-structured quote template is often enough.