I think that the biggest thing that people on this thread are missing is that the interviews' main point is not to evaluate the idea, but rather to evaluate the team; the value of the idea itself is of secondary importance in that it reflects the ideas and thoughts of the team itself. As pg has said before, one of the things that they look for is confidence. The problem, according to him, is that some people are very good at faking it. Therefore, an objective of pg is to get people away from canned routine and to be original. Therefore, if the people are smart and capable of expressing their ideas, they should do well.