Replacing the Bathroom Fan Switch

After replacing the bathroom fan for just three months, it stopped working again. The fan was fine, but the switch was dead. So the previous switch was made by Eaton only lasted three months. I hope it was the switch issue and not the electrical issue. Does any electrician or electrical engineer know why the switch had such a short lifespan? Could the cost ($0.85) be the factor? Switches seem to last for a very long time. Hit me know if you know the answer.