TouchGraph is an excellent tool that gives you “visual insight” into a site’s external linking structure and relationships, which is a good starting point for website competitive analysis.  Let’s compare Redfin, Zillow, and REALTOR.com.

Redfin’s linking relationships

Zillow’s linking relationships

REALTOR.com’s linking relationships

The visual representation of these relationships allows you to quickly explore the link structure of the “affiliated” sites much faster than conducting such an analysis using Google or Yahoo tools. Thus, you can better assess your weaknesses, strengths, and opportunities in cultivating or disabling the same or similar relationships.