Recent research has showed that only 5-15% of people on the Web are contributors (who write blog posts/articles and comments). It means that you need a significant readership to get comments. So I'd suggest being patient and not being obssessed with getting comments.

On the other hand, you can get more comments by:

• using the WP Subscribe to Comments plugin (for others to subscribe to comments to keep the discussion flowing) - there may be more than one such plugins, too
• writing about controversial topics (the opionated article "Use text instead of graphics" got some response)
• guest blogging and commenting on other blogs

Submitting your own posts to social sites may indeed be counted as spam. Unless you sincerely want to share your articles with others and you do so on a social site, related to your topic.

The key to success on social sites is:

• article, apealing to the audience (as always)
• an click-vote-inspirational title and description during subscription (you can either ask your friend or prewrite Digg/Reddit title/body in the button)
• your own social network (Digg friends for example) who also like the article and may consider voting for it (note: I do not condone spamming - only helping the best content get noticed)

There are other things you should be aware of, but those are the basics. I'd just stick to it and keep writing. I only got an article on Digg after 9 months of writing (thats more than 130 articles and 3k forum posts).

The only thing that I do not recommend is specifically targetting social sites or doing something just to gain attention. Most likely, it'll be unnatural, stick out as a sore thumb and you'll lose trust and credibility.

Instead, I'd suggest learning what your audience craves for and delivering it. If you think your content leaves much to be desired, the only thing you can do is keep writing and communicating with your target audience on forums, blogs and social sites (there may be a social site about your specific topic, too).

Cheers.