Buying products on AliExpress from major brands is typically a bad idea unless they're being sold from an official or licensed store. This is especially true for popular tech brands as you'll often see ridiculously low prices on products from brands like Apple or Samsung, which usually aren't legit on AliExpress.

Alibaba is primarily designed for businesses looking to source products in large quantities. Aliexpress is geared toward individuals looking to buy products in smaller quantities. On Alibaba, buyers and sellers negotiate prices, place orders, and handle logistics.

The AliExpress marketplace is mostly a safe place to shop online, but like any other time you shop online, you need to be careful. Remember, AliExpress cannot ensure product quality or delivery because you're buying from a third-party seller.

For the people in the United States, AliExpress offers continuous shipment to the United States. However, the delivery time remains always the question.