Is it required to renew your anti-virus license with AVG?

One of the customer reps. from AVG and i got into a debate today, concerning a required renewal of my AVG anit-virus program. AVG says its a requirement and i say “show me where it states this on the program i purchased last year at WalMart”. its not there in writing. i am wondering if this is a gimmic? i had Norton anit-virus and only paid for the program one time. that was three years ago. so, what’s with AVG? if their program is required to be renewed each year, than why is this not stated in the original CD package i purchased? is this a scam?