Dogster got rave reviews at Under the Radar too! Most impressive might be their member and advertising-revenue growth:

Dogster is a 200,000 person online pet community. Dogster's presentation started with a Dogster member running through the audience dressed as a dog. According to Ted Rangle, Dogster's founder, that costume represented their entire marketing budget for 2006. Who would have thought that a site for uploading your pet's photos to share with your friends was big business? I'm all for dogs, I might even say that I'm one of those crazy dog owners, but not sure if I'd be befriending "Lady", giving her virtual bones, sending her messages and expecting Lady to write me a message back. Well, apparently, I'm wrong. The site looks like the Facebook, for your dog (or worse, for your cat). The founder described Dogster as digital Doritos; it is fun to play around in and you just can't stop. The company has seen healthy growth since its inception and with advertising revenue from pet related stores, the company has been able to boot strap and quickly became profitable. Growth has been completely dependent on word of mouth; on average, each member tells 4 people. Who's the demographic? 80% women, average age: 32, with salaries above $70,000. What better place to advertise pet products than to people with money who are that crazy about their dogs or cats to spend time creating a web page for them online? Dogster's integrated brand campaign employs multilayered messaging to make the advertiser a trusted member of the community. Dogster will likely make money. One sexist question from the audience was: Do these women have children, and when they, can we expect them to continue pouring that much love into their dogs and into Dogster?