A username is the name of an account on this site.
When voting through a web browser some surveys only allowed identified people to vote . If you haven't got a username, you can create it by going to the create user page or by calling 02 81161899 using your mobile phone, by voting using your mobile phone in one a survey or sending an SMS to create an account.
Please be aware that a mobile phone number can only be associated with one username. So, if you have more than one username associated with the same mobile phone number, please delete the mobile number from your other account(s) through the 'preferences' page when you are logged in.