Buying Lunch with Bitcoin?

This weekend, I had occasion to eat at a food truck that had this intriguing sign in the window:

Sign reading "Crypto accepted here, with the icons of various cryptocurrencies" in the window of a food truck.

This intrigued me, because the way I understand it, it takes 10-20 minutes for Bitcoin transactions to go through. That’s why it doesn’t work everyday purchases like, for instance, lunch at a food truck.

I asked the vendor about this, and he told me that “Oh, no. If you have $APP, it goes through right away!” There was a line, so I wasn’t able to ask more questions, but when I read the reviews for the app, a lot of the complaints involved how long it took for transactions to be processed: up to an hour, in some cases.

So I suspect that the food truck guy is confused: yes, you can instantly get a hash that says to transfer X amount of Bitcoin from address A to address B. But the real question is, will that transaction actually get recorded in the consensus ledger? This is similar to the way it only takes a few seconds to write someone a check; but you can’t really spend that money until the check clears, which can take a week. But if I went around to two or three food trucks in the same ten-minute window, I think I could “spend” the same money, and only one of the transactions would clear, in the end.

In short, I think this guy is lucky that he’s only dealt with honest people. Either that, or he figures that there’ll be some amount of theft, and that’s just the price of doing business.