I'm looking at the kind of links they've always said they value the most - freely given "editorial" links in the content area of other unaffiliated websites. All the blog comments, article marketing, press releases etc that you can summon up won't create those powerhouse citations.
It takes great content and solid word of mouth to get the best backlinks. This where social media is at its best, IMO. but you've got to have a well developed presence first. Not an afternoon's project!