Because Data Doesn't Lie
Every data generated from your google analytics will be cautiously explained to you, this will help you to know which marketing is working and which is not working, helping you save money on marketing that are not working.
How Google Analytics Helps Your Business
Which country, state or region am I getting traffic, and which is not bringing traffic. Who are those interested in in what I am offering (Product or Services)
You get to know which ads setup is working and which is not working, this helps you to know what you should stop doing and what you should improve on and continue doing.
Button Click Tracking
If you are running an ecommerce or affiliate marketing, then you should know how important it is to track every button clicked and if your add to cart button is clicked or not and if you have cart abandonment and how to improve your site buttons.
Real Time Tracking
Get to know what works in real time and optimize immediately.