Since there was an office supply item I needed I decided to order it with the Staples app and pay with Apple Pay. I fired up the Staples app and searched for the the item I wanted. I added it to my cart and tapped check out. Once I got to the checkout screen I had the option of either signing in to my Staples account, checking out as a guest or tapping the Apple Pay button. Once I tapped the Apple Pay button I was able to then choose which card I wanted to use, which address I wanted to ship my order to and which phone number and email address I wanted to use for shipping the order.
Boy after reading this I imediately thought of PayPal. Guess they saw it a lot earlier. Might take more than an add though.