I had bad credit a couple years ago because I'd never had a credit card or a loan. I decided to fix it by getting a card much like this Amazon one. I attached it to my Netflix account, turned on autopay, and forgot all about it.
A few months later my credit score had skyrocketed from the mid 500's to the mid 700's.
Nothing about my income or my job stability changed in those few months. Nothing about my spending habits changed. The only thing that changed was instead of paying $9 to Netflix via my debit card, I paid via my credit card.
But this is an advantageous situation for them because they have multiple avenues to extract money. Miss a payment? Late fee. Don't pay the whole thing? Interest. Don't read every document you get in the mail? Here's a new annual fee.
I'm in a funny situation now because my score is looking pretty good, but all of the score tracking companies tell me the best way to continue improving is by getting more credit cards. How convenient.
Edit: Spelling