martinibuster - 9:31 pm on Oct 27, 2011 (gmt 0)
Putting no-follow on the contact page links will stop that page from receiving PageRank but it won't stop it from ranking, nor will it eliminate that link from reducing the amount of PageRank flowing to the other pages linked from that web page. For instance, if you have 100 links on the page and that the PageRank is split 100 equal parts (which it isn't, but for the sake of example let's discuss as if it were), putting the no-follow on the contact page isn't going to split an additional 1/100th of the total pagerank across the remaining 99 links. The PageRank is still split in 100 (hypothetical) directions.
I'm not a fan of using no-follow on the link to the contact page because the contact page might be a positive sign of quality. In my opinion the lack of a contact page may be a signal that a website is low quality. How much that could negatively impact a quality score (if it's a part of the scoring), is not known.
This is my opinion, not something I heard Matt Cutts say. I'm not one to wait for Matt to state something before refraining from an activity that could be harmful to a site's ability to rank, either now or in the future. For example, like the issue with paid links where some well known SEOs openly praised paid links [text-link-ads.com] and vigorously defended the practice in blog posts [seomoz.org] until Matt openly attacked the practice and Google flipped the switch on the Hurt Machine, causing those same SEOs to flip flop [seomoz.org]. The point is, it's good to use common sense instead of waiting for Google to tell you what to do (or what not to do). Which is why I'm willing to take a leap and say that a contact page is probably a sign of quality and it might not be a good thing to no-follow links to the contact page.