One idea could be to use the domain for an informational website about how Americans consume, consume, and consume without thinking enough about global warming, the environment, and hungry children in other parts of the World.
.us is one of the slowest ccTLDs. They hardly sell.
Selfish, while being a generic word, has very little applications on the internet. Greg's idea of a website about global warming etc. could be put to good use, but otherwise, i don't see any commercial potential in this name