This is the holy grail of my line of work, it's all about putting [non-plagiarised] stuff on your website that people want to read. To put it simply, if you have a website worth linking to, people will link to it. Thus you get links [some call this linkbait but I think that makes it sound rather seedy], for free.
Hey look at my spangly new site with all manner of stuff
Things you want to read and tell folk about
It seems simple but not everyone can do it, content has to be original, eye-catching and sometimes thought provoking. That can be daunting for a Link Monkey. This is why it is often punted out to a third party. But this is pure laziness, when I first went to Uni, I had no clue how to write an essay, but I had to learn, so must the rest of us, that is why we must professionalise SEO, it's not just a job for folk who can press a button on onlywire. And you're giving us a bad name! Directories have their place, but.......
Of course it's not good enough to just write good content, we need some of our magic to get it seen by the wider public, but you know that already......