by default all blogs have their commentators links as 'no-follow', means the Google bot will not follow that links and that links will not get any PageRank from that page....thus having a 'no-follow' incoming link is just like not having any link, as it wont get you any
PR benefit
now if you get 'do-follow' link to ur blog, the
PR of that page linking you will also be distributed to you and it will help you in increasing your
PR....higher the
PR more is the traffic
For wordpress blogs there is some plugin which converts all your commentators links to 'do-follow'..just search it........and for blogger----no idea.
