To make money, you don't want to design a site that might confuse someone. You want your visitors to quickly find what they're looking for and then write you a check. MMN confuses people because you have to find the navigational system and then mouse over each image to determine where it will take you. If they don't like what they see or they're confused, they go somewhere else. MMN is confusing.
Confusion is bad.
It's a term American kids are first exposed to in high school. All links on this page open new windows. To return, close the new window. Well, Saturn fixed their site, but here's what Saturn's home page used to look like. The area shown inside the blue circle contains the rollover links they use for their navigation.