Things Ticketmaster et al. Should Invent: find best available seats over multiple days

Sometimes people want to go to a show on a specific day, which is what the current system accomodates. But sometimes you could go on one of several days. Like any Friday is fine, really, and you'd go on a Thursday too if it meant getting really good seats. It would be really convenient if you could search for the best available seats of all the shows, or of all the Friday shows, or all the shows in the one particular week when you'll be in town, etc.