Maybe ads. Perhaps a distributed ledger about who has see what ads. That's worth money, and I'm sure marketers would love traceability. So if ad-coin takes over that would be like injecting advertising code into the "CPU registers" of the internet. I can't wait.
My god. Get that suggestion scrubbed from the interwebs. Imagine a coin that controlled all of the commerce of the world and whose sole allocation of wealth came for the production of advertisements. Ads for ads. No product. Just ads all the way down.