Content Marketing Vs SEO
SEO services do a lot of things, from strategizing the use of keywords to monitoring websites with the help of tools like Google webmaster. They deal with issues on a page level as well as a site level, many of them more complicated than you can ever imagine. So no, content marketing is not replacing SEO, because SEO activities are never going to become obsolete.
As long as there are search engines, there will be SEO. And since search engines are going to be around for as long as the Internet (i.e. till the sun sets on humanity), it’ll be a long time before you need to write off SEO services. However, that is not to say that content marketing should not be given the importance it is due. In many ways, SEO and content marketing are complementary, and you may actually be able to combine them to great effect.