Your local auto parts store prices oil lower than a mechanic can get it for, just to bring people in the door to sell them other items.

This is a well known tactic; these items are called "loss leaders". The fact that in this environment other people have successfully made video sharing websites (without a billion dollars, no less) means that the environment is competitive, even with the loss leader tactic.

On TOP of that, "Sharing videos" is not something that is required for civil society. It's an ancillary waste of time, but in no way owed to the public sphere.