[tempestn]

Amazon order emails (confirmations and shipping notices) don't say what was actually ordered, just an order number and maybe a price. So if you buy a lot of stuff on Amazon and/or don't remember what you ordered, you have to click through to find it.

Also you can't search your past emails to see when/where something was purchased; you have to remember that you bought it on Amazon, and then search there. Much more convenient to have it in your email archive along with receipts from other sources.

[KomoD]

That's not true (for all of Amazon at least), I ordered a phone case:

Subject: Your Amazon.se order of "Spigen Liquid Air Fodral..."

Has arriving, delivery option, place it will be sent to, delivery preference, order total, payment method, name+picture+link of the product(s) and order number

And then shipping notice:

Subject: Your Amazon.se order of "Spigen Liquid Air Fodral..." has been dispatched!

and finally:

Subject: Arriving today: Spigen Liquid Air Fodral...

With order number and name+picture+link of the product(s)

Which has the same (+ more) information