1. If you have a chase freedom credit card, sign up for 10% cash back for Amazon now
https://creditcards.chase.com/freedom
2. Just buy $1500 amazon gift card and load it to your amazon account. Then spend it later whenever you shop at Amazon.
Amazon aslo sales many gift cards that you can buy as well.
3. So you can ear 15000 points with this promotion. Then transfer 15000 chase freedom points to your chase ink or chase sapphire account. Then transfer to your united milage account.