its a wise decesion you upgraded with referrals in hand
it goes like this .
*you have a referral and he/she is clicking adds and when he/she reaches $1 in their PTC Clicks
,as a premium sponsor you will get $0.50 as sign-up commission from them .
*you will get this every time when any of your referrals earns $1 in their account for their ptc clicks .
*you will get this commission only from your LEVEL 1 referrals and from LEVEL 2 - 8 you will not get this sign-up commission .
*But from LEVEL 2 - 8 of your referrals found in this page
you will get $1 if they purchase premium account for $17 .