You can not go one commercial break in the USA without at least one (maybe two) WP7 commercials. They are clearly spending a metric ton of money on marketing.
I'm not surprised it's not doing well. Marketing is not enough to sell a product, you actually have to sell something compelling. And really I think the entire OS is a giant ball of fail, there is no "nice" way to put it. I'm sure you've heard the arguments already so I won't bother repeating them.
That's not to say Microsoft can't fix the platform's deficiencies, but so far they are proven themselves to be somewhat incompetent. Good luck fixing "that" problem.