Value added is also an important part of Value Added Tax or VAT, which was introduced in the UK in 1973, and already existing as such in other parts of Europe (but of course named differently, for example BTW in the Netherlands: Belasting over de Toegevoegde Waarde, which means exactly the same). Clearly it means that taxes are imposed on the value beyond that of the material itself.
An exciting concept - especially here on E2, I think - is the idea that words are the raw materials of communication. Their value added is visible when words are put together in a way that makes people read them, listen to them, be inspired by them, moved by them or influenced by them.