I’ve recently been playing with Wolfram Alpha, which pulls in some great statistical information when you search on a first name, including the age distribution of the name and the average age of people with a particular name.

All this makes me think that you could make some pretty reasonable assumptions based purely on a first name.

Take ‘Gordon’ for instance.  Most famous Gordon is probably our current prime minister.  Wolfram Alpha’s search on Gordon shows the birth dates of Gordon over time (US only data, unfortunately):

And from that data, you can generate another graph showing the age distribution of people called Gordon:

So the average age of an American called Gordon is 58 – which co-incidentally is the age of Gordon Brown.

Turning to David Cameron, David is a much more common name – but even so the average age of all Davids is 50.  Not a million miles away from David Cameron’s real age of 43.

So OK, if I could get hold of UK data this would be more interesting.  But my basic thought is that if your email address contains your first name, marketers could probably make a pretty good stab at guessing your age.