[revorad]

I know, I'm equally amused by the valuations.

It's a bit like old school advertising (billboards, TV) versus Google pay-per-click ads. As soon as you can measure something accurately, it's value decreases.

[irrelative]

Indeed. Old school advertising was sort of like a mystery box. What do you think's inside? It could be ANYTHING!

Sort of like the maxim "Half my advertising works, I just don't know which half." Well, Google let you measure which half, and improve on the other.