CORRECTION: Sorry, but the links are bad. Read the following messages.
. . . . the content of the message on a popup ad when about to look at an audiobook at Kobo/Rakuten/Walmart.
I suppose that this popup will appear for anyone, from anywhere (in the U.S., at least), navigating from any I.P. However, I was going to look at the audiobook on
this webpage. The popup popped up on both Chrome and Firefox. So, if you don't get the popup, try navigating to
this webpage"and see what happens.
Sounds like it could be a pretty good deal. $10 off would amount to a lot off of ebooks and audiobooks, to my frugal persona.
The popup will prompt you to "sign in with Walmart." Who knows the reason for that?

It could have to do with the fact that almost everyone has a Walmart sign in, but relatively few people have sign in credentials with Kobo or Rakuten.
Disclaimer: I am posting this despite the fact that I hate Walmart.