Yeah, business and design people dont always get along. I do not, however, think designers should compromise on their instincts. If you think one thing will work better than another, despite what marketers say, you have to trust your instincts. It’s just that with hard numbers (as this topic seemed to deal with, ie- percentages, etc), sometimes marketing people can make the decision seem clearer. But marketing people (just like sales people) will act like you’re stupid for not doing exactly what they say, and designers should never give in to that.
Have fun, creative people, I’m going to ogle at chairs that look like clouds or something.