[zdne]

Fair point! I'll try to answer with a question: So why is it that Google, Microsoft & Yahoo cooperate on schema.org to establish shared vocabulary?

They don't have to make it interoperable per se. It'd be enough to use some terms from a shared vocabulary (user, account, address) and then have some business-specific terms.

This way the business can use an existing library that knows how to handle user profiles. It's not that the full client has to be generic, a UI component that knows how to present a portion of a dictionary is enough.

[goblin89]

> So why is it that Google, Microsoft & Yahoo cooperate on schema.org to establish shared vocabulary?

Reduced differentiation between underlying services drives them from product world into commodity world. Lower margins and stronger competition at that level certainly benefit the big players. Services in question, maybe not so much.

[aargh_aargh]

Great counterpoint.

I guess the availability (technical possibility of building) of interoperable API does not mean that it will be used in every case. It would be used in cases where there is an economical benefit and vice versa.