Not sure if this is a Prime Day thing, since it appeared for me as a banner ad, and not on the "Prime Deals" page, but I'm putting it here anyway, since I figure most folks with interest in this sort of deal are watching this thread

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I had a "Use Amazon Pay, get a $5 Amazon Credit" banner ad pop up just now, and when I clicked through, it took me to this page:
https://www.amazon.com/b?node=23492851011
And on that page, there's a link to a list of places you can use Amazon Pay.
I didn't see a button to push to activate, which is a bit odd.
I'm attaching a screenshot as a thumbnail.
Oh, and you have to make your purchase within 7 days...
As usual with Amazon offers, YMMV - their algorithms may make sense to them, but rarely to the rest of us

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