You grew up in Reading, which you've described as "Mini Barbados". That makes it sound quite glamorous...
Back in the Sixties, Reading was full of the recruiters from the Caribbean. You had a lot of people move over to join the Royal Berkshire Hospital, including my mum who was a nurse. I grew up surrounded by lots of people from Barbados and other West Indian islands as well.
Do you have fond memories of school?
School was good. I was good at sport and when you can win trophies for your school that transcends any issues that you might get in terms of race. Kids can be cruel, but myself and my sister were popular because we were sort of an ambassador for the school. I have very fond memories.
Were you always ambitious when you were younger?
I think there was always a competitive streak and that I had to push myself. That was the influence of my dad who always said "You've got to be the best at everything and try twice as hard". Whether it manifested itself into sitting at the top of the tree of ambition, I don't know. But I was always concerned with doing the very best at whatever I was doing, be it schoolwork or hobbies. So it's about the competitive part of my DNA, I suppose.
Often, advertisers focus on children. Your son, Isaac, is almost five. Do you ever find him coming to you saying he wants the new Xbox game?
He's a bit young. He's only just started school, and he knows that mummy's job is to put out the ads in the breaks. He sort of sees things on TV, and I know what he likes, and I know he wants anything to do with Star Wars, anything to do with any form of Marvel superheroes. He is obsessed with the Star Wars Disney cartoon. But that's about it for now: I limit how much he watches in terms of screen time because I want him to learn to read and enjoy reading.
You've just been named the most powerful black Briton. Do you have any bugbears about race representation in ads in the UK?
Bugbears, no. I do think the UK is a fantastic fruit salad of people. Whether you are trying to get a soap powder or a car in front of somebody, that's everybody in the UK that falls into your target audience. When you look at the purchasing power of Britain and the growth of certain populations, it makes total business sense to be targeting them. You ignore the purchasing power of women and ethnic audiences at your own peril. The brands that have been successful at representing different groups have future-proofed their business. And there are brands that are doing it well.
Do you have a favourite advert of all time?
From when I was growing up in the Seventies there are three that I remember distinctively. R White's Lemonade, just because I remember the guy coming down the stairs in his striped pyjamas and I remember the song really distinctively. The Milky Bar kid because I was always a little bit perturbed as to why he was so Aryan. And then Coca-Cola's I'd Like To Teach The World to Sing. Since I have become a mum, it's anything with a child in it. Some of the Cow & Gate ads I love, where it's the baby creating a band in a studio session and all the kids are playing different instruments. And the Evian roller Seventies babies, I love. Those are the ones which now, emotively, I really notice.
After a working-class upbringing in Reading, Karen Blackett, aged 42, replied to an ad in The Independent for a job as a media auditor. Now CEO of media agency Media Com UK, she last month became the first woman to top the Powerlist 100 of most influential black Britons. She lives in London with her son Isaac and has homes in Barbados and the CotswoldsReuse content