At UrbanBound we are necessarily obsessed with who our users are - and who they aren't. An application designed for baby boomers utilizes very different design principals than one designed for a younger audience. If we try to design for everybody (the lowest common denominator) we just aren't going to be compelling enough to anybody. We keep a visual reminder posted of who we are, and who we deliberately aren't, build for. This way we don't waste time and limited resources on people who aren't likely to work with us.