This is the short edition of More or Less, first broadcast on the BBC World Service.

Hello and welcome to More or Less on the BBC World Service.

We're your weekly guide to the numbers in the news and in life, I'm Tim Harford. Recently the BBC's

technology correspondent Rory Kathleen Jones reported that Apple's

revenue had fallen for the first time since 2003 and he added this

by falls in the sales of what must be the world's most

profitable product in history the iPhone

but is the iPhone really the most profitable product in history?

We asked you for your ideas about what might be more profitable and you got in touch in

droves.

Does a bowl of soup or a cup of coffee count as a product? Most cafes will

regularly make 85% on this tasteful colored water. I was always given popcorn as the example of the

highest margin product.

Potato Crisps? Software? Microsoft Office or other specialist packages?

Printer ink or horse seamen. Very expensive per milliliter.

Hmm, well I think if you blended an iPhone into a liquid, it probably would be worth less per

milliliter than either of those precious commodities.

Loyal listener David works with pharmaceutical companies.

Vaiagra probably has a gross margin well in excess of 85%.

The same goes for Loesek, Prozac and many, many others.

And then again, when you start deducting things like promotional and sales force costs,

general and admin costs, R&D, transfer costs, tax, buildings and other infrastructure, then the profit falls out of the sky.

...