The worth of your business is important because it determines how much money you can borrow, how much stocks you need to issue in order to purchase another company and ultimately to understand what you really have when you finally sell it.
The value of a business is a mix of art and science.
It is dependent upon both what your business has done, but it opportunity in the future and what is happening in the economy around you. It is very dependent upon your Intellectually Property, how you price in the marketplace. (are you a commodity business), and how important are you as a principal (the more important you are, the less the company is worth).
Delta can walk you through this process.