They don't even sell music. They provide access to music for free, and charge you for access to that music without ads. Amazon's (the company) largest product

They don't even sell music. They provide access to music for free, and charge you for access to that music without ads. Amazon's (the company) largest product is Amazon (the marketplace). Amazon (the marketplace) allows Amazon to sell products to users, but also allows 3rd party merchants to sell products to users.