I don't think people realize silver is needed for electricity energy, making it an inelastic commodity. Pure silver is the best conductor of heat and electricity of all known metals, even moreso than copper.
As China and other emerging economies continue infrastructure building, developing the Detroits, Houstons, Chicagos of China, these cities will expand the demand for electricity. More importantly, the liquidity tightening is keeping small companies from getting financing to expand production, which is crimping silver supply. More demand + less supply = pricing power.