It seems to me that most people don't bother putting things on the Open Thread if it's more than five days old, and there isn't any other random tat outlet.
I wonder how much of that is an issue of trivial inconvenience. Once the Open Thread is more than a few days old, locating where it is can take more work.
A fun comic about seashells and Bayes' Theorem. http://xkcd.com/1236/