In the namespace, there are 1,000 really large businesses. Lets assume that they have 500 domain names each. Actually, lets assume instead that there are 10,000 really large businesses and but that they also have 500 names each. That makes for 5,000,000 names that are owned by really large businesses.

Who owns the other 30 million or so?

Let's not forget that Mickey Mouse doesn't run this show.