Planet13 - 5:42 pm on Jan 23, 2012 (gmt 0)
...and if you are posting links on sites which are article repositories filled with duplicate content, then Google will spot the quality of that site and de-value accordingly.
I think it was Grouch Marx who said, "I wouldn't want to belong to any club that would have me as a member."
I think if you are going to post blog comments, then you need to post comments on sites that are HEAVILY moderated. The harder it is to post a comment on that site, the better.
Then post a comment that is so compelling that the blog publisher will WANT to publish your comment and link.