Theories, yes; however, none of them have withstood careful analysis. There appears to be no clear pattern as to who is taken, nor for what purposes. The only answer that seems to stand out is, 'for their entertainment.' With their abilities, it wouldn't make sense for this to be a test of our physical capabilities, nor of our resourcefulness. It's possible this is a psychological test, but it still seems unlikely.

In the end we don't honestly know much more than we did when we were first taken here, but we are still looking for answers. Each night lends us precious few clues, but we take all that we can find and work to analyze them and seek solid answers.