Most critics pronounced his first episodes middling at best, but audiences are eagerly lapping up Jimmy Fallon's late night debut. In its first week, the comic's talk show beat all its time-slot competitors—cable and otherwise—and trumped the averages of his predecessor, Conan O'Brien. Nearly 2.4 million viewers watched the SNL alum's first week on the air, which averages out to 21 percent more eyeballs than were focused on Conan's most recent Late Night run. His initial week also posted the best numbers for a talk show premiere in the last decade. But how long will the magic last?