Yesterday, the grande dame of romantic fiction seemed to answer the question when she invited 60 'close friends' to a party in the ballroom at the Berkeley Hotel, London. Fine food and wine was being served; how nice of Barbara to invite them along.
Or was it? The lunch was a belated 93rd birthday celebration for a collection of old friends who have been close to the author down the years. But the party was belated, it transpired, because the press might not have been so available on Saturday, with World Cup football and heatwaves making much of the news.
The party was not then just a convivial occasion for friends; rather, there was the sub-text of a book to publicise. The friends were being taken for a ride.
When journalists converged on the Berkeley Hotel, it was with the promise from the author's publicists that 'a very special and newsworthy announcement' was due to be made. When the announcement came, the gasps were inaudible: Dame Barbara had written another autobiography - her fifth - and in doing so, had claimed a world record - she had made publishing history with her 600th book, the most written by any author, 'dead or alive'.
Cue a number of startled- looking guests as they walked past flashing cameras to toast their friend's health. The actor Sir John Mills found a few apt words; the Earl of Lichfield looked like a rabbit in the headlights as he dived for cover after muttering something about going to school with her sons.
But ultimately, and despite this, Dame Barbara will be forgiven, as she always is. Because her shameless self- publicising, and her wonderful vanity, are part of the creation that makes her the wonder she is.
Take, for example, the following interview she quotes in the autobiography, I Reach for the Stars.
Linda Christian, a film star, said: 'I suppose the highlight of my visit to London was surely meeting Barbara Cartland for the first time. I have met every great movie star since the 1950s. As a personality Barbara surpasses them all.'
Or the following assertion: 'Even after I had received a great number of proposals of marriage and the men had all told me that I was the most beautiful girl they had ever seen, I was still doubtful.
'Perhaps I was only convinced I was beautiful when the press referred to me as a 'social beauty'.'
For those who want to know her secret - the beauty, not the writing - it's all down to a substance called Flame, obtainable from all good health shops, and Harrods. It was a profitable day for Dame Barbara and the Al Fayeds.