What shuts down a fluther discussion of a question?

Do you typically keep providing answers until a definitive answer is provided? Do you choose to keep adding to the dialogue as you think of new things? When you choose to stop contributing, does it depend more on the answers provided or the nature of the questions? Or do you just stop when the answers have degraded to such a level that it isn’t worth following anymore (i.e., a bunch of whispers unrelated to the topic)?