I'm not talking about indexing user info -- it's more about responding to various queries during normal workflow. The link in my post above is a good example (e

I'm not talking about indexing user info -- it's more about responding to various queries during normal workflow. The link in my post above is a good example (even if I'm not sure it's very useful): you are editing some kind of document and you want to get quick, in-place info about certain words, names, concepts. Or another example is universal search in the OS (it is present in OSX, Windows, Ubuntu, ChromeOS): there is one single location where you can search for everything (local files, web stuff, etc.). That needs to be powered by something, and a 3rd party engine represents a HUGE risk if that 3rd party is one of your biggest competitors. Same goes for voice recognition, etc.