It depends on what you're doing with your website, but we definitely recommend you have a plan for this. Content is critical for optimization and "fresh" or new content is an important factor of how customers will judge your website. If you have a small business brochure website you might probably want to update twice a year some pages on your website, you might also have a page to display the latest news on your website and you can add a couple of notes once a month or every two months if you want. For medium and large business websites you might update or add content more frequently, those kinds of websites are built to have those changes as needed.