Ann Hamilton, a senior brand manager for Ubisoft has gone on record to say that Wii sales are being driven by females. The exact quote that Hamilton gave Tulsa World was:
What’s driving the Wii sales is the use of Wii by women, girls and families. It’s a really female-driven platform.

Imagine: More Moniez
Hamilton went on more about her views on females:
Girls have a very high impact on how we interact with each other. As a human race, we have men and women — and we all communicate together.
Wow, just wow. I agree that Wii sales are being helped by women, but she makes it seem as if it’s the biggest reason. It could be, but previous data released by NCL has stated the gender ratio of ownership is 50/50 if I remember correctly.
Well, yeah.