Sure I can live without most things that solve a problem, but that's not the point. I want to understand if there's some added value for the users, why would they start (and continue) using it in the first place. Jerome_etienne gave a good answer, but you also made a good point with the "invented needs". On the other hand, I'm not sure that can last for more than a couple of years on its own. Users flock to the next hot thing all the time.