Why do you have to deal with it
The usefulness of this is that customers find your business through a browser from organic search (Google, Yahoo etc.) will obviously have an interest in your products and / or services. For example, if you run a shop for pets and someone does a search on Google for the keyword "food words to dogs", then you should theoretically reach the first search results, as most of the clicking stops in early 3 or 4 organic results.
This inbound marketing strategy can be launched any time you want, but it takes a real experience and an investment of time to work. This is why most companies that need SEO will choose to seek professional digital marketing agency, IT'S like to deal in place.