People are always trying to protect us from things, but the reality is we only need to be educated to protect ourselves.
Many blog systems including WordPress have nofollow as the standard with no way to deactivate it. This may seem
like a good idea to block people who post spam comments, but the reality is that it destroy the Internet community.
You may think I am kidding, but what is currently happening is a huge number of sites are currently using nofollow.
So you comment on their sites and if you enjoy talking to the people that is great, but linking helps each other and
it helps your site rise in Page Rank. Page Rank is important as that is how you are found in the search engines.
Since sharing is what the Internet is all about, it seem reasonable to share our rankings with each other. If everyone
is not sharing then it comes to down to those who have the biggest budgets get the best Page Rank and since
they don't share that, only them and the few people they do share it with (most likely advertisers) get to share in it.
I can understand promoting community and good conversation, but nofollow doesn't do that. It just hordes large
sections of the Internet while the rest of us are their support keeping their rank high, while yours will most likely
never go above three unless you have a marketing budget.
Now I know we do marketing here, but we believe in organic white hat marketing that provides some sort of value
to our client's customers and the rest of the Internet. So I say moderate your blog instead of using nofollow. If people
aren't really getting involved then sure remove the comment, but otherwise share the link juice.