Backlinks from social bookmarking

Guys, question.
I have a blog with about 30 original articles in it.
I social bookmark each of article with Facebook, Linkedin, Twitter (nofollow), Digg, Stumbleupon, Mister Wong, Google Buzz, Yahoo buzz, Bebo, Delicious, My Space.
The problem - I have been doing it for a year and none of my backlinks came from those sites. I look at backlinkwatch and couple other sites - I still have zero Google links, but some Yahoo and other searches (about 400 in total including no-follow links). I also have no conversion from traffic brought by specified sites (well, only one of the mentioned sites really gives me a good traffic due to their news feeds).

So, why am even doing it? Or what do I do wrong?

Any suggestions?

Hi,
If you are concerned with your conversion, then i think there must be something wrong with your website's design or the domain.
In SEO we have to consider all these factors as they are interlinked to each other.
If you want backlinks, the better suggestion is to go to Do Follow blogs and comment on their blog posts using a link.
Gracious.

Yes, but social bookmarking supposed to be one of the ways to get l;inks, right? I saw a list where all above supposed to be dofolow sites.

No?

Bookmarking helps abut you cannot take it for granted that it will get you backlinks..... it is a part or SEO or SMO. It does increase your online visibility and helps along with other seo methods.... individually as it the case with you.. it will be very difficult to get back links only by bookmarking. If you want back links you should focus on getting back links from sites that are similar to your site..... or do some article submission and blog posting.