Went to an in-person local bitcoin meetup the other day and brought the couple boxes of books I had lying around.
Sold them using my Nostr wallet. Worked well.
So that was nice.
That's the quiet part: with an NWC wallet the buyer needs no channel of their own, so someone who has never touched Lightning can pay after a single scan. Where it breaks is the seller's side. A self-custodial node can only accept what its inbound liquidity allows, so most meetup tables end up on a hub wallet. No card reader, no merchant account, no chargeback window.