It has always been so.
The father of the modern manufacturing revolution, W. Edwards Deeming probably said it first in a management setting, that led to lean, the TPS, 6 sigma, and a host of management articles, cliches, and learned papers, but it has been said before, in many ways. It is also a core component of the Balanced Scorecard.
Measuring advertising has always presented a challenge, throw an ad schedule on the box, and hope it works, has been the dominant method for many years.
Now we have the net , and a whole new set of measurement possibilities across websites and social media platforms. Like anything, simplicity is the gold standard, finding a few measures that get to the heart of the performance is a real challenge for management, as differing measures for differing platforms, differing markets, and platform/market/interest dynamics are always required, there is no pro forma to be used here.
Avinash Kaushik‘s great blog Occum’s Razor concentrates on measurement of digital performance, this entry on the measurement of social media, which should engage the minds of all marketers.