It is known simply as the Oprah effect, but a personal recommendation by Oprah Winfrey is the most powerful commercial force in world publishing. A recommendation by the talkshow host will give an enormous boost to the sales of any title – although the popularity of Eckhart Tolle is said by American retailers to be unprecedented.

Oprah’s Book Club began in 1996, concentrating on fiction, although for a year she gave up books in 2002 because the demands of finding six to ten titles a year was too great.

A New Earth has been helped by Oprah’s own expanding media empire, which has seen deals to set up her own satellite radio and cable television stations – and develop her website, oprah.com.

The self-help book is being promoted with the help of ten live online seminars with Mr Tolle, and readers have raced to pick up the title ahead of the first session last night.

All the figures show that the spiritual title has struck a chord with Americans, with Oprah gushing on air that “being able to share this material with you is a gift and a part of the fulfillment of my life’s purpose”.

Such evangelising has persuaded more than 700,000 people to register ahead of the online seminar. Even if only half that number viewed the webcast, it would have been one of the most-watched events on the net.

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