Why do motherboards generally come with multiple PCI express x 1 slots?

Why would they bother with several PCI express x 1 slots? If PCI express x 16 can support the x1 than why not just have all of the express expansion slots be x16 and just use them which ever way you need to? Is there a benefit to the x 1? thanks so basically it [...] http://bit.ly/mNyLN3