As Procter & Gamble reveals the positive effect of PR on its brands, many wonder if other companies will now scramble to measure PR's benefit to them.

Procter & Gamble spends billions of dollars promoting its stable of brands throughout the world. And when this consumer-goods giant makes a marketing move, companies everywhere take note.

It was no small ripple in the pond, then, when P&G revealed that it experienced a greater ROI from PR than any other marketing discipline ...