But isn't it a slow process that requires relationship building, marketing of your content and so on because Google has made it that way after years of clamping down on link builders.
Hence the need for most online businesses to hire someone who knows how to get the kind of links Google currently likes and spend more and more time/money as Google makes it an increasingly complex and time consuming task each year (or as your competition gets better links also).
To me it seems that if you're building links purely for SEO purposes and you wouldn't have bothered in a world where links make no difference to rankings, Google might eventually find a way to kill off that activity.
Links should just be a way to publicise our sites and drive traffic. As a business I struggle to justify link building purely for SEO purposes when they could be made worthless overnight. That is a time bomb, regardless of how the links were built.