Having a web presence is almost an absolute necessity for any business. Having a web presence that your potential customers can find is the important part of that web presence. Having an seo agency work on your web content is the best way to make sure that your website will be found when someone searches for something you sell. You may have content that is so well written it should get a literary prize but unless people see it, who cares.
SEO is the acronym for search engine optimization. What this means is making sure that the things written for your website will be done in such a way to have your website listed on the first page or two of the results when someone searches for something you sell. As an example, pretend your business is pool cleaning. It does no good to have a website for the business if when someone types in pool cleaning on a search bar your company is on page 3,978 of the results.
An SEO company understands how the placement of the results are determined by the search engine. They write content so that your website will come up higher in the results so people may actually see it. The more people that see your site, the more business you will have. Unless you have done a lot of research on the subject, figuring out how a search engine decides where to put you on the list is not something you will understand. If you really want to write your own content, at least have professionals go over it and touch it up some.