Social networks can aid the bootstrapper in finding customers for his/her product on line, getting their input and employing it in marketing that startup product or business all with surprisingly little upfront money.

Two of my favorite social networks are probably MyBlogLog, now a property of Yahoo!, and Technorati, the famed blogger search engine.

I found the first through venture capitalist Brad Feld's website, gave it a try and really loved it.

The pluses of MyBlogLog, in my opinion, include:
• List of most recent visitors
• Tracking of who has recently joined the communities to which you belong
• Message board allowing for brief messages between community members
• Individual customized communities for each of your blogs

Negatives have to include:
• Tendency for spamming in the message section
• Blog communities arranged by individual blogger rather than interests, subject matter (though this can be addressed using existing functions.)
• Arranging by blog instead of author requires multiple accounts

Technorati advantages include:
• Mapping function showing who is linking to your blog
• All posts automatically reflected on the site, a function that MyBlogLog now also imitates
• Fan function allowing others to list themselves as your supporters and to be seen by your visitors

Disadvantages include:
• A draconian limit on the number of fan links you may create
• Both Technorati and MyBlogLog are centered around author rather than blog so if you've got a fleet of them on different topics some are likely to get lost since you will likely become known more for one or a handful of blogs than for all of them.