If you are constantly adding new articles to your blog, or your website is already a content-creating supernova, you may be sitting on an untapped gold mine. Once an article is published, many people simply forget about it and move quickly onto the next one.
But every once in awhile (quarterly, half-year or annually) you should consider conducting a content audit on your site. A content audit is an audit where you improve articles, merge them together, or even remove them.
There are dozens of opportunities for re-optimizing existing content on your site and continuing to reap the benefits of it. You can use tools like Google Analytics and Google Search Console to judge the effectiveness of past articles and pages.