I have probably posted anywhere from 100-200 comments on many different blogs around the net, and they have helped my PR raise and also my indexing rate of pages on Google. However, if I keep posting comments on blogs to gain backlinks am I going to really see a difference for another 100 comments? How about 500 more comments? I am just wondering if continually posting blog comments with backlinks to your site just continues to grow in value, or after a while the backlinks just don't count for as much anymore.
blog comments are good way for links but do not put all your eggs in a single basket.Try other methods too - especially the article submission.
Blog commenting is good. But they may not be accepted because of excessive spamming by others in that blog and blogger will simply remove them including good comments.