Rhiannon Harries: 'Oprah's most powerful weapon? Not coming across like a moron'

Got up this morning, day four of my Consciousness Cleanse, and found freedom through forgiveness. Managed to forgo an unholy fry-up thanks to fab new book I'm reading called Women, Food and God, then ditched usual work attire in favour of experimenting with "new ways to wear khaki".

OK, that's not quite how it was, but it would have been had Oprah Winfrey – the world's most powerful celebrity, according to Forbes' 2010 list – exerted any kind of direct influence on my life. All of the above come with Winfrey's seal of approval – the modern-day equivalent of a royal warrant, or at least in the US.

The list, like most of its kind, is patently silly. "Powerful" meaning what? The capacity to shift self-help books, or weaken the knees of teen girls (Robert Pattinson is number 50)? In fact, the best way to understand Forbes' definition of power is to go back to GCSE Physics – the rate at which work is performed (media visibility) or energy converted (entertainment-related earnings).

Winfrey's top spot isn't surprising – she's headed the list before and even on this side of the Atlantic we know that with her sprawling media she has the ear of Middle America and rakes in pots of money to boot. On every occasion, much is made of the fact that she is both black and a woman.

But this year she has company – the number two spot is occupied by another black female best known by her first name alone, Beyoncé. So what finally separates Winfrey from the pack is that she is the only talk-show host in a top 20 of pop stars, actors and athletes. Admittedly, her career now goes far beyond presenting, but it has always been the core.

The Oprah effect is unfathomable to some. Winfrey is not always a brilliant interviewer if you care for real candour or depth, and her inspirational philosophy is a bit hokey and New Age for some. I began to understand it myself only recently, when the story broke that The One Show's Christine Bleakley is getting a few million to decamp to ITV. That Bleakley is the top of the UK presenting pile speaks volumes about the talent in this sector.

All I conclude is that, however nice or intelligent you are, it must be very hard not to come across like a moron when presenting a TV show. Oprah may spend a little too much time humouring Tom Cruise and harping on about the "abundant life", but the ease and flair with which she does it is incomparable. If Bleakley's millions are reflective of her skills, then Oprah's estimated yearly earnings of $315m are surely richly deserved.