A network's usefulness is proportional to the square of the number of its users, meaning that its value grows exponentially as the user population increases.
One equals one, two equals four, four equals sixteen, sixteen equals two hundred and fifty six, two hundred and fifty six equals sixty five thousand five hundred and thirty six, and so on.
So how useful then is the Internet?
If we include all forms of networking like email, fax, (mobile) telephones, the television, communities, clubs, fitness centers, religions, and so forth, what then?
There might even be some abstract level of usefulness above which things become too complicated that the usefulness actual starts tapering off or even decreasing (exponentially).
Exploding and then imploding before we even realize what happened.