Unwatched DVDs on your shelf. Use of the word started on criterionforum.org in May 2008, thanks to a user named kevyip1 who criticized people for buying more stuff than they need, thus wasting world resources. Can also be used of other products such as books, music CDs or video games.
I admit having a large kevyip. I'm slowly reducing it with the goal of having it go away entirely sometime in the future.