An exceptionally well-written, drily inflected and amusing book called How To Produce a West End Show has plopped through the post. Julius Green's tome, published by Oberon, may not crash the best-seller lists, but it's certainly a valuable addition to the confessional memoirs of his fellow cigar-suckers Oscar Lewenstein, Michael White and Michael Codron.

The first such "producer comes clean" book I ever read was by an impresario called Henry Sherek, a big bombastic man with a monocle who formed an unlikely alliance with an ascetic director called E Martin Browne to produce the plays of T S Eliot.

Then there were the reminiscences of C B Cochran, who specialised in Noel Coward, revues and musical theatre ("Cochran's Young Ladies" were as renowned as the Tiller Girls in their day); "Cocky" was a real character, too, and was even the subject of a biographical show with the unlikely onstage manifestation of the eccentric dancer and great comic Max Wall. For some reason, the show excluded the final act of Cockie's life, which was the bizarre one of being scalded to death in his bath. 

Nothing so drastic has happened, so far as I can tell, to Julius Green, who's a quietly unassuming fellow, though, as a close colleague of Bill Kenwright, he's certainly had his ups and downs. As he grimly remarks, quoting Oscar Hammerstein, "The number of people who will not go to a show they don't want to see is unlimited." Michael White even called his autobiography Empty Seats.

Like all good producers, Julius recognises the lottery nature of his profession and the equally tenacious truth that no-one can ever prescribe a hit, or have the foggiest notion of where such a commodity might next appear.

He quotes the instance of an unknown producer, Marla Rubin, who was equipped solely with a mobile phone, a copy of Contacts and a woolly proposal for a Danish film called Festen. She had commissioned an adaptation from David Eldridge and assembled a creative team led by Rufus Norris, neither of whom Green had ever heard of. He helped her to draft a budget and wished her good luck.

After the show was an overnight sensation at the Almeida, Julius introduced Marla to Bill Kenwright, "a man of infinite good taste and wisdom," he says, who propelled the show into the West End, an expedition to Broadway and a national tour, produced out of the Birmingham Rep, and funded by the Arts Council.

"If only I had read this book when I was producing plays,I wouldn't have lost all that money," says my friend Gyles Brandreth on the back cover. I doubt if even Julius would claim he can turn you a profit with his advice, but he sure  does seem full of useful words of wisdom, even explaining why actors are wrong to make a big thing of their hairstyle in their Spotlight entries: "Hair length and colour can always be changed, and it is the producer's right to require this (at their own expense)."

Green's last chapter is wryly titled, "How to Cut Your Losses on a West End Show," something he knows an awful lot about, poor chap. He's astute about the so-called power of the Press and acknowledges the importance of the awards - welcoming the increasingly high-profile Theatregoers' Choice category in our Whatsontsage.com Awards as a corrective to the domination of "our subsidised friends" in the other awards ceremonies - but knows, at the end of the day, a show is a hit or a  flop regardless of media coverage.

"Did the critics kill the show?" someone asked Alan Ayckbourn after Jeeves failed first time round. "No, the show killed the show," he replied. "Once the critics have given their verdict," says Green, "there is also little point in attempting to "fix" a show that isn't working. It is an expensive and time-consuming process and rarely pays dividends."

I'm always intrigued by a first night audience jostling itself towards a corporate decision about the show they are watching, many of them for various reasons: friends or relatives in the cast, money in the show, schmoozing opportunities, the after-party.

The other night, there was an absolute first in my experience at the Jermyn Street Theatre when the publicist, Deborah Goodman, on behalf of the producers Joe Hill and Adam Morane-Griffiths, stood up at the end and invited the whole audience (about just forty-five of us, admittedly) to the after-party in Green's Restaurant.

I can't imagine who went, beyond the director's dad Leigh Lawson, and his wife, Twiggy, as well as Abi Titmuss (possibly sizing up the role of the croupier floozie in Kissing Sid James for future reference), big shot producer Karl Sydow (director Jason Lawson worked on his Beatles show, Backbeat) and jovial diarist and man-about-town John McEntee.

But you can bet your bottom dollar there was talk of a West End transfer, a smash hit, lights up on Broadway, and all the other crazy dreams that showbiz flesh is heir to. For me, it was the mundane alternative of a bus ride home and a three star review.