Comment by alexvaut

What about returning refillable standard cups ? You return them dirty, starbucks/mac do wash them and everytime you want a coffee you get a clean one. It existed in France for glass bottles in the last century, it's still like that in Belgium for beers (and works very well). I don't see any problem to apply it for coffee. You can even think of little stickers of the brand from where you get your coffee, those stickers will be removed in the washing process. So if the big names can agree on few cup design/material and a washing process/logistic, they will have a very durable cup!