Cross selling is possibly the most effective method of marketing in existence. It involves selling related or complementary products and/or services to an existing customer or client. Cross-selling is most common in the financial services industry which includes mortgage financing, real estate investments, tax return preparation services, insurance brokerage services, and accounting.

Cross merchandising includes the retail practice of marketing or displaying products from different categories together, in order to generate additional revenue for the store, sometimes also known as add-on sales, incremental purchases, or secondary product placement sales. It is a form of cross-selling . Its main objective is to link different products that complement each other or can logically be used in association. This strategy also aims to improve overall customer experience by allowing them to acquire related goods at the same location instead of having to spend time searching for them.

A statistic that is often cited: Companies are 60% to 70% more likely to sell to an existing customer, whereas the likelihood of selling to a new customer is 5% to 20%.

Upselling is defined as add-on or suggestive selling. This generally takes place when additional products or services are offered or suggested to the buyer of the primary product. Common examples include upgrades, a warranty, an extended warranty, or insurance. Upselling is very common in the automobile sales industry and new home sales industry.