I've found that washing the Yubikeys, especially if they are on a keychain, can be helpful. Soap and water, and then let it dry thoroughly before using it again. The theory here is that build up on the contacts make them not able to conduct as well, and so touches aren't detected. It worked for, YMMV.

I accidentally bricked one when I walked across a carpeted room and zapped it with a static charge.

My NEO has been on my keyring for several years. Still going strong.

My Yubikey Neo has been on my keyring for over three years, too. No problems at all. They seem pretty rugged.