For one thing, copied content looks boring. It doesn’t at all distinguish your own website from those of your competitors. When people go online to search for a product they want to buy, they’re also looking for a bit or a lot of information on what that product is all about. If they see that you have the same copy-n-paste description that a dozen other e commerce websites are sharing between each other, they simply won’t notice you; your website won’t stick out at all.