The bloggosphere is abuzz today about the new DiggBar but I have my reservations about the new, admittedly cool, multi-purpose link sharing tool. The concern is its impact on SEO ranking for links shared using digg short URLs. URL shorteners like is.gd are popular on Twitter, Facebook and FriendFeed because they look better and save characters. Most URL shorteners use an HTTP 301 redirect to forward browsers to the final URL which is the method recommended by Google. The DiggBar URLs on the other hand point to digg.com/<code> and use framing (nested iframe) to display the target page, a technique that was considered to be a cheap dirty trick to steal content back in the '90s. Example: http://digg.com/u13iq.

framing increases Digg's page rank, not the target

Framing has its advantages, for instance adding a digg button to any page, but it's bad for SEO page rank because search engines will see those URLs as links to digg.com, not the actual page. I thought that Digg might be checking the user agent string to detect the Googlebot, Yahoo Slurp or other indexers but after testing with the User Agent Switcher Firefox add-on and with Javascript completely disabled, DiggBar URLs always use framing.

If page rank is important to you I would suggest that you not use the Digg URL shortener. Instead, choose from one of these that use 301 redirects.