Well you kind of do contribute to Uber's value for others by using it and not other service, but not as significantly as with social networks. You use an app, d

Well you kind of do contribute to Uber's value for others by using it and not other service, but not as significantly as with social networks. You use an app, drivers see there is a demand for it, more drivers, better service, you ever so slightly increased Uber's value against its rivals. This is true for every service, only the value of individual contribution differs: huge for facebook, pretty big for "real life" businesses (uber, airbnb), quite minor for "online only" (non-multiplayer videogames).