I think bike valet parking is a excellent way to raise ridership. It does two things well. 1) for those who might bike anyway, it reduces one of the barriers of finding a parking spot near a busy event. That’s usually a small barrier, but Concert on the Square is a huge event each summer week in Madison. 2) for those less likely to bike, seeing a throng of bicycles very near the event makes biking look normal and may contrast with having to park one’s car much further away.