Our Big Debate poll is back! And we're centring on an issue that has come into sharp focus with the recent 25th anniversaries of both Les Miserables and The Phantom of the Opera, as well as the upcoming Olympics: What effect do longrunning shows have on their audience and on the West End generally?

Readers of Whatsonstage.com will know that our annual Awards feature categories for Best West End Show (won this year by War Horse) and Best Takeover in a role (won this year by Les Miserables' Alfie Boe), making us one of the few theatre awards to recognise the merit of long-running shows.

We know from voter numbers that several productions attract large fan-bases; we also know from our ever-lively Whatsonstage.com discussion board that many of you visit these productions multiple times. But just how many times? And what is it that keeps audiences coming back? It's time to find out...