When is 99% less than 99%?

By Brian Clegg

Asking when 99% is less than 99% sounds like a riddle – but it’s not. I recently heard a Sky Mobile radio advert in which they claimed 99% UK coverage. In the ‘small print’ words at the end, they said this meant they covered 99% of the population.

I don’t know about you, but unless I’d heard that proviso, I would have assumed that 99% coverage meant you could connect to their service in 99% of UK locations – I expected the figure to be based on area of coverage, rather than population.

It might seem like this is splitting hairs, but it really isn’t.

Let’s just imagine an unlikely version of the UK where 99% of the population lived in London (this is, after all, what most advertising people think). Having 99% coverage by Sky’s definition would mean that you could only use your mobile phone in 0.65% of the country. The whole point of a mobile is to be able to use in on the move, not just at your home location.

Of course, the real UK is not like my imagined version. Yet the country has far more open space than many assume. Only around 10% of the country is built up. This means you could make Sky’s claim and still be inaccessible in much of the other 90% of the country. 

In saying this, I’m not just getting at Sky – I’m sure other mobile providers make similar dodgy claims. From my own personal experience travelling around the country (using O2, not Sky), quite often I can’t get 4G and there are plenty of places still with no signal. 

If you want to use statistics in your advertising, it’s a good idea to use numbers that mean what people will assume they mean. Otherwise, it’s more than a touch deceptive.

I have contacted Sky to ask about how they came up with the 99% figure, but as yet have had no reply.

Image by Resume Genius from Unsplash

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Now Appearing is the blog of science writer Brian Clegg (www.brianclegg.net), author of Inflight Science, Before the Big Bang and The God Effect.