Since my biography of Jennie Churchill was published last September I have given more than forty talks to a wide variety of libraries, schools, dining clubs and reading groups in this country and the U.S. I realise how fortunate I am to have so much interest in my subject and I love talking about it. After six years in isolation, either researching in libraries or at home writing, it’s wonderful to meet one’s readers. Even the critical ones. But last week, as I crawled home after driving 500 miles in 24 hours on the day petrol prices hit $135 a barrel, I wondered if I had now become not a writer but a talker. Perhaps a travelling saleswoman even and a crazy one at that. I have done little else in the last nine months other than touring and talking.

Of course, I realise it is not me as much as my topic that is bringing in the invitations. Fame by association. This means that most of those who invite me hope that instead of “just a writer” they will get someone related to a celebrity. I am not, of course. And my efforts to avoid too much disappointment are expensive; hairdos, manicures and the odd new outfit. One lunch event, themed around Ascot Ladies’ Day, even required a hat. Well, to be honest, the hat was not compulsory but a good excuse for some retail therapy so beloved of my subject. I didn’t want to let her down.

But it’s also very time-consuming. Each audience demands a slightly different angle – (Stratford on Avon wants to know about Jennie trying to raise money for a Royal National Shakespeare Theatre; Brooklyn wants to know where Jennie lived as a child and for how long, St Albans obviously needs to be told about the ten years she spent living there) and a different style. Some want PowerPoint for 30 minutes, some for 50, some want a half hour talk before dinner with the second half after dinner with no pictures and some want you to talk about your writing in general with only oblique reference to the book you are trying to flog.

And it’s emotionally draining, not to say exhausting, because giving a talk is a bit like a performance. Post Cameron, we must all learn to speak from the heart, without notes. But I’m not trained as an actor – nor am I meant to be one – yet audiences expect to be entertained as well as informed. Most importantly it has to sound as if this is the first, not the 39th, time I have said whatever it is that I am saying. More than one librarian has handed out evaluation sheets and charmingly told everyone, while I stand there grimacing, to be frank in their assessment.

Last week, putting my all into a performance, I saw a few hunched bodies trying to creep out unnoticed before the end. When I realised I was competing against a Manchester United versus Chelsea match in Moscow I understood how lucky I was to have anyone in the audience in the first place.

Only rarely does this effort and expenditure result in large sales. Often, an audience feels that, having paid for the talk (and or lunch) they’ve spent enough and learnt all they need to know. I have had people rushing up to speak to me, shake my hand even, and then present a blank autograph book for me to sign. Once, I was shown a first edition of My Early Life by Winston Churchill and asked not to touch at all let alone sign anything. As for payment …I have received bottles of wine and champagne, including one very special bottle boxed with my own name and picture on the label, a key ring, a magnificent boxed set of opera CDs, bath oil, chocolates, flowers, a plant, free tickets to other events at the festival, a lunch, a dinner and a bed for the night, and a 1945 copper plate photograph of Winston.

Money? Hmmn. Not usually.

To ask is this cost effective just isn’t the right question. So why do it? Because it is wonderfully rewarding. The benefits are beyond money. I have been to parts of the country I never knew. Okay so Croydon or Blackburn may not be top of your ’10 places I must see before I die’ list, but the drive from Blackburn to Oldham across the Pennines is breathtaking, the walk around the Lake District and view across from Fowey to Polruan magic. Those benefits are incalculable.

And I have met some inspiring librarians and booksellers who have restored my faith that, in spite of all the negative publicity, books do still matter in people’s lives

So this is neither a whinge nor a boast because any writer with time, determination and a good story can do the same. I am always flattered to be asked and it’s a great way to give to charity far more than I could ever afford to give in a cheque. I have spoken at a charity event which raised enough money to fund a scholarship in Sarajevo for a journalist in my name. How could I ever hope to endow a scholarship any other way? And, after one talk, I gained a new anecdote about my subject which gave me real insight into her character and which will definitely find its way into the paperback and which even Jennie’s family had never heard.

But there is a serious point to be made here. All authors shudder at the phrase ‘we just don’t have a budget’. So when is it reasonable to ask to be paid in cash and when should one accept gracefully and gratefully the invitation to speak knowing that at least some books are being shifted?

The Society of Authors has guidelines advising how long following publication of a book talks are usually unpaid; after that asking for payment is reasonable. Festivals have their own rules. But even so, it isn’t always appropriate to ask for a fee. Especially when things go wrong. I have been held up in traffic jams and arrived unavoidably late. I have had my pc refuse to connect with the projector. There was one occasion when “a modest honorarium” had been promised but, as only six people turned up for the uncomfortably intimate talk, I felt I could not accept anything at all.

But there are also some very real benefits. If a bookshop that is part of a chain invites you then their intranet carries details of your book, alerting other shops in the chain. The manager of the local bookshop in Sidmouth may not otherwise know that your subject had a life affirming affair while staying there if you don’t tell her and offer to come and talk there. The potential value of a leaflet circulating to mailing lists of the charity or school where you are talking gets your name to thousands of people. They may buy your book on another occasion or at the very least talk about it. I had my picture in local libraries for a couple of weeks, which might have been useful publicity had they not tried to enlarge a picture from my website and stretched me until I resembled an alien with a face the shape of a mango.

The night I talked in Preston, at the University of Central Lancashire, in aid of the University Bursary fund, my reward was a large tub of ice cream, just for me, alone, to devour in my hotel bedroom afterwards. It had been home-made by the owner of the bookshop, Silverdell Books of Kirkham run by the enterprising and delightful Elaine Silverwood and Sue Wardell., selling books that night, a new: Manhattan Cocktail-flavoured ice cream created especially in honour of Jennie Jerome. Now that’s something money cannot buy.