How Long Do You Give Shows to Get Good?

Photo: HBO

How long will you stick with a show, based on hope alone? Over at Gawker, Brian Moylan complains that he's "sick of waiting" for shows to engage him. (He gave Luck two episodes; he gave Treme two seasons.) Is there an appropriate time frame? How long do you wait before getting show-divorced? Have shows like Mad Men or Game of Thrones given you a false sense of trust for other series that start a little slow? Or have shows like perpetual-punching-bag The Killing made you wary? Are there slow-burn shows you're glad you stuck with? Or do you look at, say, Boardwalk Empire and realize those are hours of your life you'll never get back? How much waiting can you tolerate?