An interesting thought

Looking through all of my email just a few moments ago I started to wonder why exactly I have more than one email account. The answer was inevitably that I get junk mail at some, mail from people I don't like at some, one that I tried to use, and one that I actually use and could be construed as being over-used. My question became, "On average, how many email addresses do people who use email have?"

I am open to suggestions. My guess is 2, on average. I would bet that the median number is actually around 4.

Also, why do you think we all have so many accounts, is it services offered when you sign up, the overwhelming amount of junk mail, the annoyance of people that send too many forwards, or just that they are free and free is good?