It goes back to what I was saying about some stuff is great for social marketing, whereas other stuff is just not. Mad Men (and season premieres of popular television shows) are obvious examples of great uses for social marketing because the conversation is authentic. The authenticity of the buzz is key because people know advertisers are in the web 2.0 world. With natural buzz it is very clear that influencial people in a persons life care about the brand.
Advertisers can nuture the buzz to create a greater ripple effect throughout the web. Case in point the "Mad Men Yourself" game. I noticed a friend had posted his on facebook, asked him about it, found out what it was, went to the site to do one myself, and now I am here blogging about it some more. I had no idea this person was a fan of the show, so now, I'm sure it's something that we will end up discussing or buzzing about.