Is this a new career for web writers?
Newfangled Web Factory has an article about content strategy and a better description than the one I came up with myself.
What is a Content Strategy? Put simply, content strategy involves identifying the type of content that will best enable you to communicate your positioning and achieve your online goals, then planning for the creation of that content by allocating time and resources to the effort.
I found my first mention of Web Content Strategy on the site of the same name which has a blog to explain more and give updates on the industry/ career. I found other resources which I will link below:
Content Strategy: Free Online Resource for Web Editors and Content Managers.
At Dosh Dosh you can read about why content strategies are important.
A List Apart kind of pulls it all together in a shorter article.