Ehefrau just bought three 0,33L cans today. One with cherry and the other two with vanilla.
Actually never tasted them before since i only had the stock Dr. Pepper ones when i lived in the outskirts (USA)
You can find Dr. Pepper in almost every grocery store here, but judging from the quantity of cans and bottles and the space they have reserved for them on the shelves, they don't sell that many i guess.
So they're more like a niche product here.