Fresh content is king and a key to higher SEO ranking
By adding fresh content - at least publishing one new thing daily - you will continuously place your content before the search engines and keep the attention of readers. If someone comes to your website, forum, landing page or online community, a couple of times and everything is still the same as the first time they came, you have probably lost a reader because they think there is nothing new to learn from you. The search engines respond in a similar manner: no fresh content, no recommendations for more traffic.
On the opposite side of that coin, if you continuously ping search engines with your new content, fresh articles, videos, e-books, landing pages, press releases and social media content, then they are enticed to crawl your site again and again. They will index the new content and hopefully build your position as an authoritative source in the process.