Once again, I am a newbie, but from what I have read(which is an awful lot, and my head hurts), it's better to concentrate on one blog/campaign and get that right first.

If you are promoting any product, you should do yourself a favor and take advantage of every single free backlink-creating resource you can. SO, to summarize what Trevas and Curtis said...

Articles about your topic, use a resource box at the end with your link(I submit at least 3 different articles, to 8 different sites like ezinearticles etc.)
Blog about your topic
Place links to related articles on your blog, as well as to your own
Post on other's related blog topics and forums or groups, sign with your link
Create a lens(squidoo), link to your blog, lensroll related lenses
Create a hubpage, link to your blog, your lens, etc.
Link lens and page to your facebook account.
Register at all the sites on SocialMarker, and then use the service

Basically, there are so many other free traffic avenues, a blog is really just the tip of the iceberg. I set up a list for myself, and check off each step as I go. Just be sure that you are linking back in each instance, and that you are refreshing content regularly.

Good luck, I hope this helps. I know how frustrating it can be, believe me!!