I swear i have 3 google accounts, of which none i actually use. they all get sent to my hotmail account.
I have never made one, i have just been given them, my uni and my school have gave me an email, that has been google.
Seeing how that is thousands per year, assuming it is accross the UK, then no wonder they have gained so many users.
Also i have only ever had 2 spam emails in 8/9 years, and that was my own fault, of signing in when i had a virus on my pc, other than that i never had a single one.
I'm even an IE user.