Sales and Marketing: Separated at Birth?

I hear this question a million times over, and I scratch my head in wonderment every time: "To achieve the growth we are targeting, do you think our company needs to focus on marketing or sales?"

The question perplexes me because it makes me wonder why so many otherwise smart businesspeople fail to see that marketing and sales are inexorably linked. You can't focus on one without the other; what's more, they must be tightly integrated and reinforced.