Link Building

[CostumeJewelryStores]

No follow links from relevant niche does help. When google talks about 'natural' link building, it pretty much means that sites cannot and should not have just do follow links. A site with ONLY do follow links would be penalized, as it is so unnatural.

[Kasi Viswanathan]

When I comment on any blogspot after it getting approved.

when I check the commented page and clicked on view source, when i check that it's re="no follow" attribute.

As this is a no follow attribute does Google consider this back link for this page to increase my PR.

and also I noticed that all comments which I made on blogspots turns into no follow attribute.

Please let me know the reason.

Thanks in Advance....

The reason for the rel="nofollow" attribute is safety precaution from google for the commented blog. Because Google giving Penalty to Unnatural Back linking websites.
Because Back links are sale from lots of website so Google decided to use this way.

The website relay recommending site then only dofollow links otherwise use nofollow links.

nofollow links will not consider by the google. And the Page rank will not flow to the nofollow links.