OK, so this post's title is a little bit hyperbolic - and much of the content of the article has been known for a long time. But it's still worth remembering the basics. 

A single marketing "campaign" sketched out pre-launch and delivered has long been on it's last legs. Even a campaign planned out in advance needs to be refined and improved after each push - with careful analysis of what works and what doesn't. 

A great tip here is to use "evergreen" content - but update the messaging, the targeting and so on over time to remain relevant. 

And of course, always automate where possible! Modern marketing automation tools like Pardot allow you to build out your nurture programs in advance, but tailor your messaging and your audience over time with little additional investment.