Hands up who had electrons for Christmas?
Many years ago I realised that my job in computing could be reduced to the description of "pressing buttons." A very simplistic one, but that is how it felt. Certainly a computer programmer spends most of their time pressing buttons. But as many jobs involve use of a computer nowadays, many jobs can probably be described as "pressing buttons" too. A friend of mine worked in manufacturing. He had an open day at the factory that he worked at which I attended. He showed me the machine that he used. It had a single button. He wryly showed us the button he pressed as if that was the sum total of his job. That was probably what was the seed to lead me to describe my job as pressing buttons.
A similar reduction can be done on Christmas presents. When I was young I got things I needed; socks, kettle, toaster, tools etc. As I got older and wealthier I got things that I didn't need; socks, radio controlled helicopter, singing snowman etc. Always the presents were things that you could see and touch and in the case of CDs, hear. You could say that presents consisted of molecules.
Then came the Kindle and digital music. With the Kindle and digital music came the possibility of buying electrons. The data is downloaded over the internet (wired and possibly wi-fi) to the target computing device to play or read the data. The data is transferred in the form of electrons, hence "electrons for Christmas." Amazon in the USA allows you to purchase a Kindle book as a gift for someone else. Amazon UK doesn't allow you to do so, yet.
So what next? Presents were molecules, now they are smaller i.e. electrons. Fibre broadband is being rolled out across the UK so next they will be photons. Soon people will be having photons for Christmas!