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I do not know if I invented it but I did use it :)
btw, do you see that there is a random whale at third place ( ͡° ͜ʖ ͡° )

Permissionless and trustless peer to peer (although via a central server) advertising. I guess this has already been invented through advertising spam in comments sections, but this might actually be one of the first permissionless advertising opportunities where people don't get annoyed at you for promoting an idea.

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