This morning, the head of Google’s search spam, Matt Cutts, posted a video where he strongly recommends that anybody please placing widgets on their sites, or those who distribute widgets, should place a nofollow on the links within the widget code.
Matt Cutts said, “I would recommend putting a nofollow, especially on widgets.”
The reason he says that most people who embed the widget on their websites don’t realize what other things they could be putting on their website other than just a widget. So, if the purpose of the widget that you are embedding is for a poll, it may end up also containing a link back to the poll website without a no follow on that link.
Google is telling the widget maker to add a nofollow on that link, so if the person who is adding the widget code to the site won’t be passing PageRank back to their site without knowing.
Despite that being said, that does not necessarily mean that the link contained in the widget will be worth as much as a true editorial link in terms of ranking.
Matt also mentioned a few times within the video the infographic example of embedding infographics on your site.