I am sure some of you noticed I have not posted for the last week - and for that I'll ask for forgiveness. I was out of the country and didn't have access to a computer for any appreciable length of time.
But to address George's point:
In theory, a properly stored tire can last a very long time in storage. The key is how close to "ideal" are the storage conditions. Changes in the rubber take place very slowly if there are no outside influences. Obviously heat is an issue, as well as the presence of ozone from welding, electric motors, and other sources of ozone - both natural and man-made.
Clearly, it is next to impossible to have freshly produced tires always avaiable at the retail outlet - particularly considering the number of tire sizes. Sometimes, a particular tire will only be produced once a year. Winter tires, for example - where the market demand is so seasonal.
If we take into account that MOST tire storage in the supply chain is somewhat reasonable, then a tire that is 2 years old is close enough in condition to a newly made tire that it can be considered the same. Even 3 year old tires - and in particular tires that have been stored in tire warehouses (as opposed to the "shed" at the tire dealer), can also be considered reasonable close to "new".
However, once a tire has been placed in service, the heat and stress generated during operation change the rubber in the tire. Again, the changes are slow, but accelerated compared to a stored tire.
So how is the best way to express this - in simple terms - so the average consumer has some guidelines as to where in the process his particular tires are? Needless to say, this is highly imprecise.
I think the point of the news article is that SOME tire outlets pay little attention to the storage conditions of their tires.