I know it sounds a little ridiculous, but I think Google still has a long way to grow. I can easily see them as the first trillion dollar company and well beyond that.

I think they understand the process of re-inventing themselves better than any other tech company. They acquire a lot of companies, some of which continue to grow and change the very nature of Google itself (example Android). They also understand Black Swan Farming and practice it at a level (billions of dollars at a time) that almost no one else does.

Andy Rubin's robotics undertaking is a good example. Page wrote him a billion+ dollar blank cheque and should it succeed, it'll make Google the leading robotics company - likely alone worth as much as Google today. Should it fail, well, it's only 2% of their cash pile. They've made similar bets on almost all promising future tech - AI, clean energy, the internet of things etc.