Get your customers to link to you
If you have partners you work with regularly, or loyal customers that love your brand, you can capitalize on this by sending out partnership badges—graphic icons that link back to your site (like Google often does with their AdWords certification program). Just as you’d get customers wearing your t-shirts or sporting your bumper stickers, links are the best way to accomplish the same feat on the web. Check out this post on e-commerce links for more.
Build a company blog; make it a valuable, informative, and entertaining resource
This content and link building strategy is so popular and valuable that it’s one of the few recommended personally by the engineers at Google (for more on this, see articles at USA Today and Stone Temple). Blogs have the unique ability to contribute fresh material on a consistent basis, participate in conversations across the web, and earn listings and links from other blogs, including blogrolls and blog directories.
Create content that inspires viral sharing and natural linking
In the SEO world, we often call this “linkbait.” Good examples might include David Mihm’s Local Search Ranking Factors, Compare the Meerkat, or the funny How Not To Clean a Window. Each leverages aspects of usefulness, information dissemination, or humor to create a viral effect. Users who see it once want to share it with friends, and bloggers/tech-savvy webmasters who see it will often do so through links. Such high quality, editorially earned votes are invaluable to building trust, authority, and rankings potential.
Earning the attention of the press, bloggers and news media is an effective, time-honored way to earn links. Sometimes this is as simple as giving away something for free, releasing a great new product, or stating something controversial.