Sam has an iPhone 6 Plus and he's going to be upgrading. He wants to know how he can sell his old phone. Leo says he'll get the most money by selling on eBay, but Apple will buy it back and he can just trade it in for the new iPhone 7 Plus. There's also Gazelle. They will give him a good price because the resale value is very high. His carrier will also buy it back, as will Best Buy, but at a fixed price. Gazelle will probably give him a better deal.
(Disclaimer: Gazelle is a sponsor)