Hi! :)

Using an up-selling campaign will allow you to offer the customer a higher quality product that will be perceived as premium goods, by clearly marking the features or parameters that determine the higher standard of the product. When the customer decides to buy a new phone, we can offer them a model with a better camera, bigger memory or a completely different phone, which is newer and has better parameters. If the consumer decides not to go for the proposed model, they will opt for the model they originally chose, which will ultimately result in a profit.

Cross-selling consists of offering additional products when the customer is already decided to buy in a given store. This campaign does not involve any risk, because in the worst case, the customer will buy only the basic product, which they chose from the offer himself. The purpose of the cross-selling action is to remind the user about products that may prove useful or even necessary in the near future. 

When the customer adds a laptop to the cart, we can offer theman addition of a keyboard, mouse, headphones, bag or appropriate adapters. These are products which are often bought in later stages, and recommending them at the stage of selling the basic product may result in the consumer considering buying the whole set at once. This action can generate more sales and reduce the likelihood of buying accessories from competitors at later stages.

Cross-selling and up-selling and their basic principles of use: 

https://blog.salesmanago.com/marketing-automation/7-up-selling-and-cross-selling-ideas-using-marketing-automation/