you can easily make your blogspot blog dofollow, for encouraging other blogger to comment on your blogs. most of SEO experts keep on searching dofollow blogs. step by step easiest method you may found on my blog. Blogspot dofollow
I do not agree to make my blog dofollow because in this case the world will tend to leave spam comments. if you leave it nofollow, those who have something to say, they will do it without having any benefit from it. but that's just my opinion.
of dofollow it's not good idea for blog, You can get a lot of spam, this trick is easy, you can do that yourself if you know a little bit HTML