I've seen a few family members with it, they say it's to build credit, and the Signature Card charges to direct fee (at least, one that's separate from Prime membership). My cousin (he's 19) bought it, mistaking it for a gift card, realized how dumb he looks now, and wants to cancel the card day of it arriving.
This paragraph mischaracterizes the situation to such an extent that I will simply assume you don't know what this card is.
https://www.amazon.com/Amazon-Rewards-Visa-Signature-Card/dp/B007URFTYI
1) There is no "direct fee".
2) It's a credit card. You can use it to build credit. You don't "buy" credit cards, you apply for them and either get approved or denied. Your cousin got approved.
3) It offers 5% cash back on all purchases made on Amazon.com. This is a great rewards program if you use Amazon prime. I would use it whenever I want to buy anything off Amazon. If you know how to handle credit cards, handle this card just like that.
Same here. I wonder if we're talking about different Amazon cards; there seem to be different versions.
Prime store card from Synchrony (what I have)
Prime Rewards signature card
Edit: Actually, you mentioned Chase, which implies you have the Rewards card, not the same one as me. Which in turn would kill my idea that this is specific to one card or the other, since you and I both see the same thing.
Edit again: OK, I see it now. On the desktop app, there's no way to expand the payee that I can see, but on my phone, I can look at a transaction and get all the details like OP mentions. Which is cool and all, but unfortunately, I rarely use the mobile app. :-/
Yes - the Amazon card is managed through chase - you can either get the prime card which is 5% back or the regular card which is 3% back https://www.amazon.com/Amazon-Rewards-Visa-Signature-Card/dp/B007URFTYI
https://www.amazon.com/Amazon-Rewards-Visa-Signature-Card/dp/B007URFTYI
Always use your Amazon points to pay the bill. Don't purchase with them. Otherwise you lose the 5% your get by paying with the card.