Interesting article about hyper-segmentation at Read/Write Web:
Let us take a look at the social networks available for parents; in this category alone we have Cafe Mom, Maya’s Mom, MothersClick, MommyBuzz, MTV’s ParentsConnect, Famster, and Minti. The niche for parenthood seems to be taken. Yet, it can further be broken down to, say, “Grandparents”, “Stay at home mothers”, “Single mothers”, etc. Becoming a master of any of the smaller niches has many great advantages, such as less competition, loyal readership, and better focus.
Couple it with the Segments & Lifestyles series of research, and you may well have a small business that can be bootstrapped for $100k.