Wolfire Games Blog has a postmortem of the recent Overgrowth and Natural Selection 2 preorder bundle. They offer sales figures on the unusual bundle of two games that are still in development, and a great deal of analysis of the response to the promotion. Word is: "The promotion greatly exceeded all of our expectations and blew up to be the biggest thing to ever happen to us. We sold more preorders in one week than we had sold in a year, previously." Thanks Shacknews.