My sister, a retailer, didn't see it that way. It cost her something. Her normal (coffee-shop) transaction is cash. This scheme is a big loss for her.
If everything is on the level, then there's no loss.
I didn't consider tipping culture. A scourge.
I have to know beforehand how much I'll need, and keep that separate from the rest of my funds. This means that I can't use it for anything that would normally come directly out of my account, and can only be used for in-person transactions.
You are over-simplifying the entire process.
What am I missing?