Upselling (sometimes ‘up-selling’) is a sales technique whereby a saleperson induces the customer to purchase more expensive items, upgrades, or other add-ons in an attempt to make a more profitable sale. -wikipedia
I’ve become a victim of upselling and amazon.com admitted to me they were doing it:
When you add an item into your cart, amazon redirects you to a page with more suggested items. I just can’t believe their URL gives it all away. Classy!