Facebook innovations aside, social networks can be important to bootstrap entrepreneurs operating on line even if they don't allow direct sale of your product or service.

Indeed, one of the main focuses of the new guest posting network I announced earlier this week at PostRanger.com is based around the idea of social networking.

Social networks can benefit the bootstrap entrepreneur by:

• Increasing visibility among a large number of potential clients and customers much more quickly than might be possible with an individual blog or website

• Improving PageRank and traffic for your business site with links from a much larger and well established website with a large user base

• Providing a good platform to make important announcements about changes in your business that might otherwise be missed by those not yet regularly visiting or subscribing to your company blog

• Allowing you to find and network with potential partners, clients and customers in an interactive environment where you and others can search member profiles based on common interests and other factors

A laundry list of social networks not mentioned in the previous post (most of which are free at least on some level) includes:

• Virb, a site that allows collection of a wide variety of media and information in personal profiles

• Xing, an on line social network specifically for business professionals

• MyBlogLog, one of my favorite social networks and the one on which I began building a network for the Bootstrapper's Club

• The Bootstrap Network, a global social network for bootstrap entrepreneurs

• hipFOX, a social network for NFL fans

• YouTube, the best-known video social network (Revver and Blip.tv are two other examples)

• LiveVideo, sort of a cross between YouTube and MySpace

• Second Life, possibly the most unusual social network of all featuring motional avatars

• Yahoo! Groups, somewhat old school but still an ideal format for interaction in a small group setting. Our own Bootstrapper's Group is only one example.

• Me.com, an interesting tool that allows you to create your own social network based around a central theme of your choice.

Any other suggestions? Leave them in the comment section.