Getting emails from random strangers is one of the side-effects of my job: sometimes it’s a perk (they like my book, or column, or whatever), other times it’s a death threat (a consequence of saying something mildly contentious on Question Time), but recently, a whole new category of unsolicited correspondence opened up. I had mail from a woman in, I think, Canada, who is so desperate to see David Tennant and Catherine Tate in Much Ado About Nothing that she is mailing any reviewers she can find online, to ask if they will try and get a DVD version of it released, maybe for charity. I can’t, obviously. I don’t even own a video camera. But I think the fact that someone wants to see a play so much that they are willing to try this strategy might begin to explain why London’s West End is having such a boom.

Last week, Theatreland reported that box office takings between April and June were up 2% on the same period last year. This came as a surprise to the industry, which saw a 6% slump in the first quarter. They’re now back on track to take over £500 million this year. And perhaps more surprising still is where the money is coming from: though the juggernaut film musicals remain at the heart of the West End (Ghost, Dirty Dancing, Priscilla et al.), the real increase is coming from plays, whose audience numbers are up by 13%.

Star vehicles, like Kevin Spacey’s Richard III at the Old Vic, or indeed Tennant and Tate in Much Ado, are responsible for the surge in audiences. So I hope this news might hush (to a stage whisper, at least) the inverted snobs who have spent years muttering that the West End isn’t the same now they let people off the telly have a go on it. Kevin Spacey is a mesmerising Richard - I doubt I will ever see a better one - and the fact that he is in Horrible Bosses at your local multiplex has no impact on that whatsoever. If you don’t like Gavin and Stacey, that’s fair enough: me neither. But James Corden gives a tremendously warm and funny performance in One Man, Two Guvnors at the National, and the fact that he is better known for being on TV than for his earlier appearance at the National in The History Boys doesn’t detract from it at all.

In fact, the reverse is true. These shows sell well and generate word of mouth in advance precisely because they have star power. Good luck buying a ticket for the upcoming Anna Christie at the Donmar Warehouse: it might be a sell-out because London has discovered the beauty of Eugene O’Neill, but I think it’s more likely to be the fact that Jude Law is the lead. Most producers need to know they’re backing something that at least has a chance of doing well, and adding a film star to the mix improves their chances considerably.

The smaller theatres punch way above their financial weight: the Donmar’s Frost/Nixon, starring Frank Langella, transferred to a bigger venue, then Broadway, then to an Oscar-nominated film. No mean feat for a theatre that seats 250 people. And the Menier Chocolate Factory revival of A Little Night Music ended up on Broadway with Catherine Zeta-Jones in a Tony Award-winning performance.

And while the casting of Jonny Lee Miller in Frankenstein might mean that an equally good but lesser known actor misses out on the part, that actor can still get cast in the play, and make a huge impact: Tom Edden may not have the lead in One Man, Two Guvnors, but he comes very close to stealing the show. All actors will tell you they’d rather be working than not working, and if that means playing a part that isn’t the lead, they’ll live with it. Especially if it means being in a sell-out West End hit, rather than playing to six people in a cupboard.