The fundamentals of marketing is based around crafting and delivering a message to an audience.  Technical SEO helps us deliver the value of that message to searchers and search engines, and is akin to using proper grammar in an article. But the limits of technical SEO appear when we consider an already well crafted message.

Now, I can make adjustments to help stand out, such as bolding my CTA to make my advertisement pop a little more, but as I begin to try to overoptimize my ad by "tweaking" the appearance rather than the message, I end up doing myself more harm than good by appearing desperate for attention.  

So, yeah, in short, content and the message conveyed in that content is crucial to the success of any marketing campaign, digital or otherwise. And no amount of tweaks will help deliver a crappy message or sell a crappy product. 

-RJ

Content itself isn't marketing. The right kind of content, promoted to the right people, in the right way, as part of an overall marketing strategy-- now that's marketing. I personally don't create content, but I do help manage a team of writers and designers that produce it. I help generate content ideas that will help us accomplish our SEO and other marketing objectives, then do the outreach to put that content in front of bloggers & influencers.

I agree to Takeshi's point. We always had content producers, but it makes more sense from an SEO and an ROI point of view when content meets SEO and Social. Even though everyone today in the industry does this (content + seo + social) strategy, the ones who excel are those who balance it out the right way to make sense to their business. For ex: a financial company might have to focus more on in-depth content and less yet targeted outreach while a publisher might want to do shorter, snappier, fun content with more outreach. Two cents.

So clearly we need to know what type of content works and why - which is a combination of SEO and content marketing skills - but is our job as sn SEO creating content which users want to see? I would like to think that technical on-site SEO and skilled outreach are all too important to replace us with copywriters, but who knows what Mr Cutts has in store for us!