It's a nice theory to embrace for those outside of the U.S. as it reinforces a vision of Americans as insular and frightened of the world when other nations' TV schedules are often a little more pluralistic. It also means that when non-American productions fail in the U.S. market it can be blamed on American xenophobia, as opposed to any weakness in the production itself.
What does Facebook sell? You could say advertising. They sell advertising to the tune of several billions of dollars each and every year. If Facebook is a media company, we then have to ask ourselves: What kind of media channel does Facebook provide and how does it compare to those other media channels?