This market is ruled by ideal model of demand and supply. People get interested in the new technology and are excited about generating some money on their own.They have demand and partially create their own supply. Others simply want to buy some coins, so they form demand, but the supply should be provided by others. What is essential for the increasing of bitcoin's price is limited supply. There cannot be more that 21 million coins, so when new people will join the market, they'll have to divide the btc that's already circulating. Plus, bitcoins are also generated in limited amounts each 4 years or so, which means that even though some day there will be more of them, people who want them now have to pay more.