I, regularly, do not use a virus scanner. I never have. On rare occasions, I have used a virus scanner to do a sanity check, and my sanity was assured. LOL. However, I do not have the usage patterns that others do. I do not download very much, I do not visit sites that could be considered questionable, I know what to look for in incoming e-mail that may contain a virus payload, I run a Linux machine as a firewall and router using a hand-configured IPTables as a firewall, ad nauseum. LOL.
IMHO, it is easy to avoid getting a virus, more so now than when I got my first internet account because most ISPs and e-mail services scan all incoming e-mail. I have never seen the value in paying for virus scanning, and I probably never will.
I know someone who installed "Panda Cloud" (http://www.cloudantivirus.com/) and says its great. It is also free. Norton is just making propaganda because their business model is threatened. My suggestion to them is that they find another market area where they would truly serve their customers instead of bleed them to death.