The Dogster Case
It seems "Dogster, Where Every Dog Has A Webpage!" is now profitable. I really like the The Dogster business proposition - "a minimal self funded startup costs, focus on a specific community/demographics, value created to the user base through a clever combination of services driving repeat visits and premium subscription, viral growth, advertising/affiliate marketing revenues and eventually (hopefully juicy) sponsorships." Unfortunately, if you're hoping to repeat their success they already have a Catster. There is some hope however as Hamster doesn't appear to have noticed the market potential.