Explain amplification of a signal in hormone action? What is its role?

Although hormones are present in very small amounts, they effectively regulate many physiological processes. This is the result of signal amplification, an increase in signal strength. For example, a single hormone-receptor complex can stimulate the production of many cAMP molecules. In turn each cAMP can activate a protein kinase that phosphorylates many protein molecules. In this way, a single hormone molecule can activate many proteins.