The key question that everybody has when they go to the world wide web is a simple one: "What do I need to know?" Different web companies give different answers to that question:
Wikipedia: You need a summary overview sketch of a particular person, place, thing, or event that you already have in mind--and we will provide you with such a sketch, written by a tag time of altruistic left- and right-libertarians and by some people who care too much about the topic.
Google: You need to know what pages on the internet have been most linked to by others and that contain keywords that you already have in mind.
Facebook: You need to know what your friends and your friends of friends already know that you do not.