Is this purely a function of sharding liability across a conglomerate of businesses? It seems like concentrating Google's ad revenue in a smaller, more efficient business unit is a nod to Berkshire Hathaway's method of business.

I can't recall this sort of thing happening in my lifetime, so it will be really interesting to see how this plays out. I also wonder how this would be treated if Google didn't have the crazy corporate structure they have now (where public shares are essentially non-equity and non-voting).

http://economix.blogs.nytimes.com/2014/04/02/the-many-classe...

Edit: I am reasonably certain this is a tax and liability optimization strategy. It allows their more risky units to operate with separate liability from their cash cow.

Edit 2: I'm actually surprised the stock value hasn't tanked because most of the future potential of Google just got moved outside of the company. How much of Google's future value was based on X? I would say a non-trivial amount of the stock price is the anticipation of future profits, which are now no longer a part of the company the stock is intended to index.

Edit 3: Disregard Edit 2, I misread the release the second time through and assumed X was not part of the company :).