Cross-selling is a sales strategy where a seller promotes additional products or services to a customer who is already making a purchase. The goal is to encourage customers to buy complementary or related items that enhance the original purchase or meet additional needs. This strategy is commonly employed in various industries, such as retail and e-commerce, where suggested or bundled products are presented during the checkout process. Effective cross-selling not only increases the average transaction value but also enhances the overall customer experience by offering relevant and valuable add-ons.