Michael Gray has written a great piece at Search Engine Land on how stories promoted in a social media site have actually translated to higher rankings. He takes a bunch of unpopular domains (e.g. not Forbes, Jalopnik, or other known car sites) and shows how their rankings have improved after the particular stories have been submitted to a site like Digg. Then he looks at the keyword rankings for each of these stories. It becomes obvious that social media is an alternative to link building but that it's imperative to use your keywords that you want for ranking in the Digg submission.
Of course, there are links to be gained, but there's obviously a lot more -- direct sales, awareness, and then some.
So why is it that you haven't tried social media marketing yet?
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