I have one facebook account with a totally fake profile that I used once to view someone's photos. I'm done with facebook, but I guess my once-only fake account still counts towards the growing number of facebook users. I am surprised by how pervasive facebook is. I insist that people post their photos on flickr or some other service because I don't want to use facebook. They in turn insist that I sign up to facebook…
You're in the absolute minority with your fake profile. I've been a heavy fb user for 5 years and can't recall the last time I saw a fake profile.
I would absolutely hate to use my real profile as I find the whole 'incoming' side of it intrusive and desperate.
The last thing is need is to have to deal with all the useless drivel people would be expecting me to take part in with a real profile.
I would also say that at least 4 of my friends do the same.