There is a shortage of agave, the plant that makes tequila. The plants take 7 to 8 years to mature. Only 17.7 million agave were planted in 2011. It takes 42 million plants to supply the 140 registered tequila companies. Demand is not meeting supply.
The shortage is expected to last until 2021. Expect prices to go up. You may need a drink just for that!