I have an English friend who's always having her books published in the U.S. Myself a Brit, I tried to sound casual when I said that my own book, Fame: What the Classics Tell Us About the Cult of Celebrity, was to appear in America. I told her that it would undergo a little tweaking. "Oh," she said, "you mean where you have to call William Shakespeare ‘the famous British playwright?' " I chuckled along with this, and reminded myself to tell new readers that David Hare is a famous British playwright.

But I was going to have a bigger problem, as discussions with my editor at Picador, David Rogers, made clear. I had written a book in Britain about famous people. Suddenly it really mattered if I was mentioning people unfamiliar to Americans. We had a lot of dialogue about how much people knew about Jade Goody, if Natasha Bedingfield is as big in the U.S. as her publicists tell us, and what on earth to say about Piers Morgan.

I learned a lot. I learned with some delight that David Hare is well-known enough to need no gloss, but that Piers Morgan, whose memoirs take a while to talk us through his appearances on Celebrity Apprentice, needs a little more explaining. And where British stars failed to glitter visibly across the Atlantic, we debated U.S. equivalents.

But even this was more complicated than simply taking out Jodie Marsh and putting in Anna Nicole Smith. (And besides, you really don't want to know about Jodie Marsh. What with Snooki and Long Island Lolita, you have plenty to cope with already.) We constantly asked if we were coming up with the right equivalents, or if new names were telling the right story.

My favorite example comes from when I mused about what might happen if so self-denying a character as St. Augustine were to launch his Confessions in London today. My point was that he would never have a party at the Groucho Club—but that locale clearly needed translating. At first David was keen to find St. Augustine the best restaurant in town, to make him feel as out of place as possible. But once I'd explained that the Groucho is more trendy/Boho than chic, he told me about Elaine's.

As the cliché reminds us, a challenge can be an opportunity. Modifying my book was a chance to look at the world as it had changed since I wrote the U.K. edition in 2008. Back then, Barack Obama was an underappreciated junior senator from Illinois, and Michael Jackson was planning his comeback tour. My book, which asks if the relationship between us and the famous has evolved, now had to come to terms with how quickly that evolution is happening.

I came to realize something I'd tried ignoring before: how vital a blog is to an author. But this wasn't just a case of writing a few words about how I write or what I happen to think of the world today. I was considering real characters, whose stories are squiggling away even from my broad overview of what happens to celebrities.

So Picador came up with Popcropolis, a Web site more elegant than anything I could have conceived: it means that I can keep assessing celebrities in light of my ideas. This isn't to say that the book's out of date; it's just that it is spawning an online appendix.

Sometimes in the U.K., writers do heave a shrug when delivering their books to America. But I discovered that it's a chance to give a project new life. At the other extreme, some British writers produce books that they consider selling in the States as the priority, which can become a little transparent, and tells in the language as well as the content. I feel lucky to have had the best of both possibilities: to have had the chance to re-evaluate what I had written, and also to relive it, to test those ideas about the cult of celebrity in the light of information. And just when I thought those theories were going to break, I would study Celebrity Rehab more closely, or the memoirs of Larry Flynt, and all would be well.

Picador published Tom Payne's Fame last month. Payne blogs at www.popcropolis.com.