Inventing a new way to turn dog poop into coffee cups is, technically speaking, innovative. Thus, any discussion of innovativeness is not tremendously useful without also considering the value the invention brings to market.

Part of that is necessarily clever marketing, but some portion of Facebook's value has to be real, new tech that makes a lot of people's lives better. If you can't point to any single thing, maybe it's the packaging of a lot of single things that is innovative?