If I'm not mistaken... I believe it's just for statisical purposes. So Alwil can get an idea of just how many people use Avast4Home.
As for the exact information?
That is up to you.
Many other users here go by other names.... so it is completely possible that people use different names.
To be honest... I don't remember Alwil asking me for a phone number when I signed up? That option is not in
BOLD leading me to believe you can leave that field empty.
Your NOT going to get a phone call though.
Welcome aboard!