Your time, and the crude attempt to model what you consider to be worthy of your time, so that people with money can waste it in just the right way to make you do what they want you to do — watch an ad, buy a product, vote for a policy.
For the benefits that it gives you, I don't see that as a waste. I can keep in touch with all my friends around the world, and I can organize trips, parties, dinners, get invited to weddings, see the new baby of a friend, etc... I'm tired of only reading the bad side of this story.
Of course, every example you just gave can also be done with email, and email doesn't hide things from you just because seeing them means you spend less time using email.
Your time, and the crude attempt to model what you consider to be worthy of your time, so that people with money can waste it in just the right way to make you do what they want you to do — watch an ad, buy a product, vote for a policy.