Lean content marketing involves creating quality content across various platforms like blogs, newsletters, social media, and guest blogging to drive traffic to a site, gain new users and newsletter subscribers, and shape a brand. It is important to target the right audience and put in real effort, even if taking a lean approach, as there are no shortcuts. Quality content marketing grows an audience over time, as seen with Brazen's blog growing from 10,000 to 100,000 monthly unique visitors in under two years through a focused approach on core writers, SEO, and syndication partners.