http://www.wired.com/2014/09/ethereum-backers-raise-15-million/Bitcoin are valuable because theyre both useful as a currency and in short supply. Only 21 million bitcoin will ever be created. Thats not the case with Ethers. Buterin and company plan to produce 15 million of them each year on their blockchain. Theres another important difference too. You will need to use Ethers in order to run software on the Ethereum network. Buterin calls it the platforms programming fuel. The 30,000 bitcoin sale is a bet that people will actually want to do this.