How is Vtune useful?

VTune is intel's optimizing program, similarily AMD has a program to optimize to the AMD processor. Depending on who your target audience is might depend on what you are optimizing for. VTune is simply a program to find "hotspots" in your program, it works in conjunction with VS.

It suggests ways to optimize certain parts of your code and shows you execution paths and more. Kris Kaspersky also wrote a book on optimizing code, unrolling loops, aligning data for cache, ram timing, called Code Optimization: Effective Memory Usage. It shows you how to use the basics of VTune and optimizing code, its a must if you are are learning about the subject.