Scratch and sniff marketing?

Snap has filed a patent that…

introduces specially-modalized stickers, that when used in a chat, allow the recipient at the other end to experience certain scents. This is achieved by the recipient interacting with the sticker on their screen through a tap or rub, triggering the release of the associated smell.

Of course, this depends on device makers adding the necessary underlying tech to make it possible. (Which is why so many platforms want to be device makers.)