Shane said: If people are only buying Wii Play because of the controller, Nintendo's wasting their advertising dollars. This explanation doesn't cut it for me. Are some of the sales coming due to the controller? Yes, no doubt. Are all of them? No, plenty of people have played Wii Sports and liked it enough to pick up Wii Play, on top of the heavy marketing campaign. If people are stupid enough to not realize Wii Play is made by Nintendo, they shouldn't be allowed to play video games unsupervised.
I would also assume that not every single person who bought Wii Play purchased it because it had a controller. Given that it's sold millions of copies, saying that "every single customer" bought it for any specific reason is probably a bad idea.
I can tell you this, Shane: I work in the Games department at Toys R Us. I have never, ever had anyone come into the store and ask me for "any game made by Nintendo," or any such thing. I've had tons ask me for "that game that comes with a controller." Parents don't tend to even know the name of the game, let alone who developed it. They just know it comes with a controller, and little Becky or Johnny needs a second controller to play with his friends.
Again, not suggesting that this represents every purchaser. I'm saying it represents most of them, and that very few people are literally buying this game because it was technically developed by Nintendo. Lastly -- please don't mock people who don't know who developed each game they purchase. In a lot of cases, the people purchasing it aren't going to be playing the game at all: they're buying it for their child or friend. Even for those who are going to be playing it, the particular development house really isn't a significant issue.