I have tried both using blogs www.Credit-and-Collections.com/blog and my newest Mosquito Marketing for Authors blog http://michelledunn.com/mmblog and www.BizCreditPolicy.com as well as My Space www.myspace.com/michelledunn to promote myself and my books.  I had heard of My Space but thought it was a place for teens or kids, the description on their website is "a place for friends".   One afternoon I was reading an issue of Entrepreneur and they had a story about a woman who said she had used My Space as a marketing tool for her business.  My first thought was "there are business people on My Space?"  So I checked it out.  I found there were very few business people that were active members, and a lot of teens, younger kids, musicians and people looking to party and meet other people with similar interests.  I also saw that they have groups and some do pertain to business while some seem as if they are business related but are "Get Rich Quick" groups.  There are groups for anything you can imagine someone might have an interest in. Many for authors grouped by genre. I thought I would try it, since I like to try everything to market myself and my books and it was free!  I created my profile page, uploaded my pictures and began browsing the site for other business owners. 

In the beginning I  met a few people that I network with but I did not have a huge response or increased traffic to my website or orders of my books because of my myspace page.  It is a fun way to meet a few other business people but you also have to weed through the emails from people just "hanging out" there and sending you emails about dating or partying.   I have left my page up and do check it occasionally as well as post to my blog. My Space page also comes up when someone does a search on Google or Yahoo for me, so that is a bonus as well.  If they find me on My Space and then visit my website, I have accomplished what I started out to do.

Update! - I have had much more success using social networks to sell books, get my name out there and network with others. I have had journalists and reporters find me through MySpace as well as FaceBook and LinkedIn.  I have met other authors and people who have bought my books and consulting.

I would recommend using social networks as a marketing tool, if you use them effectively you can make contacts, network, and make sales.

Good luck!