I'd argue that brainpower is not their only asset. It's an important input, but not their most important "asset". True assets can't walk out the door one day and not come back. People can do that, at any time. I'd say that Google's best assets are their vast technology infrastructure that's been "proven" and optimized for performance, reliability, etc., plus their brand and their existing userbase inertia. Employees can come and go. They are very useful and valuable. But Google's codebase and hardware isn't going to simply disappear one day on a whim. Folks like Guido and Vint Cerf and Thompson and Kernigan, etc., just might. Plus humans have egos and ambitions and dreams, and get old and tire or lazy or want lifestyle changes. Code and machines do not. A true asset can be sold off like a commodity. An employee cannot be sold off like this, not directly and explicitly anyway.