A2 milk was interesting phenomenon in NZ. It exploded onto the market with some seriously dodgy technical / nutritional claims, got ridiculed, and faded away. I'm not even sure if it's still stocked at my local supermarkets - if so then not prominently.
Last couple of trips to Aussie, A2 seems to be a major player, as well as prominently displayed in supermarkets, it seemed to be the default premium brand in corner store etc. Was the milk in every fridge in every home I visited too.
Perhaps aussies are gullible.