Web traffic is important for different reasons, depending on the business type. While some companies rely on web traffic for online sales, others are simply providing informational services to their potential and existing customers. Either way, it's still important to know who is coming to the website and attempt to find out how successful the visits actually are.
It's one thing (an important thing) to get users to a website, but if user experience is poor, then the website is flawed in its design, content, or both. Getting a handle on user experience can be achieved through analytics.
As a website is planned, designers and content managers make educated guesses about what users want and how they will respond, but there is no substitute for live data. Fortunately, websites can be adjusted based on user habits and patterns to help website owners achieve desired results, whether that means sales or submitting information, etc.
Finding out what your web traffic means and how it's funneling from page to page is a responsible step in maintaining an active, thriving web presence. It's the difference between guessing at what your website's value is and actually knowing what it is. Every business should be interested in the latter.