Every website needs to be found on the 1st page of Google. The infographic below shows a graphical representation on what is needed to get to the top of Google. Any web master or web site owner must understand that these days their is no getting away with not doing something to update your website. The search engines will always rank a website higher which has good content and regularly updated.
Every website should have a Blog and should be actively using Social Media. Using a blog will definitely help with SEO and will also help with social media as you can very easily.
Graphic provided by Mike Jackness