How often do you have to replace a keyless fob?

My keyless fob (the battery or circut - not really sure) died last aug 08. The dealership replaced it for free since it was under warranty. Now 9 months later, it died again. This time, my car is no longer under warranty and they want me to pay over $150 to replace it. Do these things really die every year? Also is there anything out there that says they have to replace it for free since they already had to fix this problem 9 months ago?How often do you have to replace a keyless fob?it should last at least 3 years - depends if it keeps getting pressed in your pocket