Norton has a low market share anyway which would go some way to explaining the lack of Norton PC's with a virus.
Also the demographic of people who take a PC into a shop would be those who as has been touched on would have just goggled Free AV and ended up with AVG.
At the end of the day people will have had differing experiences with AV products depending on their usage type.
Brett works in a PC shop so probably see's more than some others on these forums. However as has already been said its just a flash poll of who takes PC's into where Brett works. All he can do is base his opinion on personal experience the same as the rest of us.
There is no right and wrong just people wanting to be sure the OP gets a full picture of the true state of affairs and a decent spread of opinions so that they themselves can make a balanced and informed decision.
At least that's why I'm here typing.
Mactronix