If you have a website from which you are trying to make money, you must have visitors to that site in order to do so. It is a little like having a store in the local high street or shopping mall. If no-one ever finds your store and wanders inside, then it does not matter how classy your products are, or how competitive your prices, you will never make any sales until you start pulling in potential customers.
The same rules apply in the world of online business. No visitors to your site is exactly the same as no potential customers walking into your real world store and no sales. Therefore, you need to adopt tactics and methods that will make sure that your site enjoys hundreds or perhaps even thousands of visitors a day.
There are lots of different ways of doing this, and once your business becomes better established, you should use every traffic generation tactic that you know of to maximize the number of visitors that you enjoy.