Matt Cutts, one of Google’s Quality Engineers, posted a video that clarifies the question of whether URL shorteners pass PageRank and anchor text.
It appears that URL shorteners, such as bit.ly and goo.gl (Google’s new URL shortener service) will pass both PageRank and anchor text. According to Matt, any well-behaved URL shortener that uses a 301 redirect should pass both PageRank and anchor text.
PageRank is an inheritance value assigned to a web page primarily based upon the quality of the links pointing to the page. It is also referred to a “link juice.” Link juice includes other inheritance factors, such as the anchor text used in the hyperlink text. Anchor text is a powerful tool that reinforces the keyword theme for the receiving page. That means that a link to a page about PC repair services will have more beneficial SEO value if the words “PC Repair Services”, or something similar, are used as the text for the hyperlink.
The video also clarifies that links that use the nofollow attribute will not pass PageRank, so that means that most links from Twitter will not pass link juice. However, although most social media links do not pass PageRank, they are increasingly becoming important with Google for ranking purposes. They therefore do have value other than PgeRank.