You make me laugh, seems like you follow first order logic in a human discussion.

Let me speculate what would happen if Google applied your thinking:

- You could not integrate Google Adwords with Google Analytics because there were part of different companies.

- Android could not integrate with Google Search Engine because it was only part of a mobile innitiative.

You can play yourself combining the acquisitions listed on: http://en.wikipedia.org/wiki/List_of_mergers_and_acquisition...