andycambo - 8:15 am on Oct 9, 2013 (gmt 0)
I've looked into this recently and went with not adding 'nofollow' to the links after reading Google's guidelines. Mainly because of these two reasons that Google mentions: -
Untrusted content: If you can't or don't want to vouch for the content of pages you link to from your site.
Paid links: A site's ranking in Google search results is partly based on analysis of those sites that link to it. In order to prevent paid links from influencing search results and negatively impacting users.
I was thinking if that Google see that if you're website has 'nofollow' links pointing to it then they may use this data to suggest that website isn't trustworthy.
Perhaps I'm reading too much into or I don't think Google is trustworthy...