It's absolutely no surprise to me that Glee's doing so well for E4 every Monday night. Yesterday's sixth episode, "Vitamin D", attracted 1.09 million viewers, making it the most-watched multi-channel show that evening. Glee has generally hovered around the 1m mark since its debut six weeks ago, peaking at 1.3m with episode 4.
Its UK success is no surprise to me for a number of reasons, not least Glee's general quality, because (a) it's perfect recession-beating fun, (b) it appeals to a fairly broad demographic, not just the teen core audience, and (c) it's constantly being praised on Radio 1 the morning after, who also play that week's standout song.