I repeat the part of my comment that you did not understand "Yeah, most of them will last a lot longer than the printed date, because chances are you won't buy them and install them on the day they make them."
I am talking about bulbs that should have lasted 2 years of constant use, 12 years of actual, use, but I had to replace 8 months after I bought them.
If they had a 2 year past manufacture date guarantee, it would solve my problem.
But to be honest, I did not even try to return the curly bulb 8 months after I bought it. But I seriously doubt a normal retailer would have accepted it's return.
So that is why I want a guarantee printed on the bulb, based on constant use from date of manufacture. To get the manufacturer to stand behind their product, not screw everyone over ridiculously.
What good is a 2 year "sell by" date on a product that the manufacturer says will last 15 years? Does that really provide the consumer with useful information? The buld doesn't age appreciably when it's sitting on a store shelf, so what good is a fake "expiration" date that has no correlation at all to expected lifetime? All it will do is drive up the cost of bulbs when merchants and manufacturers have to carefully control inventory to make sure they don't have bulbs sitting in a warehouse long enough to appreciably affect the expiration date - and merchants may be left holding unsellable inventory as consumers dig through the boxes to buy "expires March 2015" bulbs before the "Expires January 2015" bulbs even though there's no real difference in expected lifetime.
If you're going to ask for a change that makes a different to consumers, why not require merchants to exchange bulbs for X years after purchase, and require manufacturers to do a mail-in exchange for the full advertised lifetime? Purchase date (well, in-use date) is much more relevant than manufacture date.
That said, I exchanged two 6 month old CFL's (expensive high wattage lamps) at Home Depot when they burnt out within weeks of each other, but others from the same purchase were still running fine (and 3 years later, they are still fine)