Will Facebook help drive more traffic to your website or Twitter? Are incoming links from Digg more valuable for improving your site’s organic rankings than than from YouTube or Flickr? Which is the best social site for engaging with people who are already in love with your brand?
For answers and ideas, check this handy chart (PDF) from cmo.com that compares the benefits of sharing content on various social media websites and whether they are worth your time or your (limited) social media marketing budget.
Some of the points mentioned in the chart aren’t valid anymore like your site won’t derive any SEO benefits from Flickr or delicious.com as they nofollow all external links. On the other hand, Facebook has a huge potential for driving traffic especially if you have a public page (example) that is indexed by search engines.