It seems daft, but this is half the price of a renewal from Norton of an already installed Norton anti-virus. Why do Norton shoot themselves in the foot like that?
It's easy to renew an existing install of Norton anti-virus with this just by typing in the 20 character key on each of the PCs that have it. Don't need the CD at all for a renewal.
Anyway, Norton Anti-virus is good, I've been using it for three years or so now, and it has continued to be assessed as very good indeed by the technical reviews in the PC magazines. I've learnt that if you just keep using the same anti-virus product every year without a thought you can find yourself with a product that has become comparatively not so good any more.