Upselling involves offering a complementary product, accessory, or service related to the main purchase in order to increase the transaction value. It can be done by a salesperson in a store or through an online recommendation system. This practice includes two forms: complementary selling, where the product is directly associated with the initial purchase, and offering an additional, unrelated product, taking advantage of the customer's presence. Upselling differs from cross-selling and can represent a significant portion of revenue in certain sectors.

The concept of upselling involves showcasing the different available variations of the same product. These variations may offer more options or higher quality. The main objective is to demonstrate to potential or existing customers the advantages they could gain by choosing an enhanced version compared to the base product. Generally, the focus is placed first on the base product to attract attention, then on the premium models to close a sale and generate higher revenue.

Upselling, or incentive selling, is a sales technique that encourages a customer to choose a more expensive or higher-quality product or service than the one they initially considered. This strategy aims to increase the average purchase amount by offering premium options, additional features, or complementary services. It can be implemented through direct or automated interactions, particularly on e-commerce platforms via recommendation systems. Upselling differs from cross-selling, which involves offering complementary products rather than upgrading existing ones.