Content is one of the greatest needs of a website, without content you don't have visitors. Be sure to fill your website with as much content as possible, otherwise you won't attract visitors, nor will you be able to keep them. For blogs, content are posts that have a meaning, not random rants but I guess that would count too, depending on the niche your blog falls in. For forums, it is topics, posts, and even articles. All things that will be noticed by search engines and visitors. You should always dedicated at least three times a week to add fresh content, even more times if you wish to get a lot of visitors and more pages indexed in Google, Bing, etc. There are ways to make the content on your site more exposed to the public, so you can attract readers. There is also ways to make money using that content and by getting those visitors to take some time and read what you have written on your website.