Domino's Japan is apparently doing a form of marketing research called a "fake door test", where they show some new product ideas in the menu to see if people try to order them. Those that order the item get a popup with an apology message and a coupon offer.
Anyhoo some people saw the items, and tweeted about it, and this site wrote an article about it.
People that clicked to buy on fake products were given a coupon for potato fries with ketchup.
This is a thing, according to the article, already - “fake door testing”
Meta: shouldn't submissions be in English? Just checked the guidelines [1] and it doesn't actually seem to say that, which might be a good addition unless I'm just failing to see it.