The "Alexa buy me expensive headphones" is a bit unfair towards Amazon. I'd guess the intended purchases are those where you know enough about the product that

The "Alexa buy me expensive headphones" is a bit unfair towards Amazon. I'd guess the intended purchases are those where you know enough about the product that you don't need to look. So if you order a certain brand of coffee or toilet paper regularly, you can order those without being too concerned. Things that you realise you're out of when walking around the house and want to re-order them before you forget.