By content, we mean the information, data,  videos, posts, articles, whatever your site is housing that draws your users to it.  You may have heard the comment "content is king"; this means that users want good content over every other feature you offer on your site. 

Therefore, every site, regardless of level of content, needs to have a content management plan.  No site is self-managing without thoughtful and planned human intervention; without the management plan, sites become stale and out of date, which reflects on your organization.

One of the biggest misunderstandings I see time and time again about web content management is that the technology is somehow responsible for content updating, and that the right technology tool will enable content, without the need for offline processes.  While it is true that technology can hinder or support your content producers, technology by itself can do nothing.

• Content does not write/edit/post/approve itself without human intervention. 
• Web writing is a skill that needs to be taught, with guidelines specific to the purpose of your site.

There is also  the curse of the commons: when updating the website is everyone's problem, it is no ones responsibility. Sites then become very uneven - some portions are up to date (perhaps with their own focus and messaging), while other, equally important sections, are stale. Your organization's content is not being represented by what is important to you but by how important your individual staff place updating the website.

If you are planning on an organic, "crowd sourced" source of content, remember that in most crowd sourced sites, 90% of the population reads only, 9% edits someone else's stuff, and only 1% post fresh content. When you have over 1M users, and a broad topic base, that content model makes sense. But when the number of content experts who have the required knowledge to post to your site number in the three or four digits, you are going to need facilitation and moderation. And they do what they want, when they want. http://www.nngroup.com/articles/participation-inequality/