This is just further proof that good reviews don't always = good sales and vise versa. Sometimes a game has a certain appeal to it that the majority of the game reviewers, at least the core ones, don't pick up on. Games like Game Party, Carnival Games, Cabela, and now Just Dance. Definitely not my cup of tea, but I realize that certain people may find this game appealing so more power to them. To each his own
I think the female market is a really underestimated one, especially in regards to Wii sales, and a lot of the games that we scratch our heads when they sell, such as Ea Sports Active, Just Dance, Boogie, etc, sell to this female audience. I am actually getting my sister the Jillian Michaels fitness game because she likes her workout videos.
Wii really is a console for everyone, which is why it gets so many sales.