Perhaps that's because the evidence has already been stated clearly?
Here are the stats:
"Women account for $7 trillion in consumer and business spending in the United States, and over the next decade, they will control two thirds of consumer wealth.
Women make or influence 85% of all purchasing decisions, and purchase over 50% of traditional male products, including automobiles, home improvement products and consumer electronics.
BUT 91% of women say that advertisers don’t understand them."
(via http://thenextweb.com/socialmedia/2012/01/24/the-top-30-stat... )