[speleding]

I can't find any reference anywhere that what you say is true, can you point me in the right direction please? As far as I know, the complete opposite is true for the Li-ion batteries that Apple uses, each discharge reduces its life.

Cadmium batteries have a memory effect and need to be drained every once in a while but Apple doesn't use those.

[semanticist]

While each full charge cycle reduces the overall life, Apple recommend going through at least one charge cycle a month: http://www.apple.com/batteries/

This isn't the same as 'run it down to 0% and then fully charge', though, it could be 'run it down to 75% and then fully charge, four times'.