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One immediate scenario that comes to mind for me is a photographer. It'd be like two million sats instead of two hundred, and the platform cut would have to be way less than what @lamplighter is proposing, but photographers do this all the time when they don't have a paying gig. Just show up at some event and send out watermarked photos to the people running it with an offer to sell non-watermarked ones if the potential client likes what they see. That alone is a huge market.
The more I think about it, there are so many things in the real world that would run smoother like this. The barrier with this though is that I don't know a single photographer that wouldn't immediately ask how to put this in quick books. That's been the single biggest response I've gotten from musicians about Direct Current. All my non-bitcoiner friends that are either self-employed or run small businesses are absolutely paranoid about getting in trouble over taxes.
Sounds like you'd be interested in OneTimeNote, or more simply, Privnote. Why involve a payment?