Some here say that the difference lies in rational vs emotional appeal, with nerds being presumed to be more "rational." But I think the difference is somewhere else. I don't think nerds are any less emotional.
A lot of traditional marketing relies on a thing where the marketer tries to sell the consumer some feature of a product in a way that does not involve delving into details of the product (this avoidance is seen as good thing -- often the fewer details are specified, the more polished the marketer considers the message to be). To a nerd, that avoidance is a very bad thing, because a nerd prides himself on knowing the details. So the marketing message that avoids details and tries to sell some "powers" that work "out of the box" hurts the ego of the nerd. This feeling of hurt is certainly an emotion, so I wouldn't say nerds are less emotional!