I learned that there are 3 ways warranty eligibility is calculated:
* If sold by Apple directly, the exact date of purchase is recorded. If Applecare is added, it's entered as well.
* If sold by a third party reseller (authorized or not), and Applecare is bought and the customer registers it, Apple trusts what the user enters for the purchase date as valid. This will only work for current generation models.
* If sold by a third party and the user does not buy/register Applecare, they assume the machine will be sold within 3 months of manufacture, and uses that date as the "purchase" date.
This is a good point, and something to be aware of.
When buying from a 3rd party reseller, especially of a previous generation closeout, the purchase date in Apple's records may not be accurate. I had the same experience buying an iMac about three months after the new one was introduced. The purchase date was backdated three months from the actual date.
I was told by various Apple employees that it wouldn't be an issue, just show your receipt, but I didn't trust their verbal promises and sought to correct it with Apple and have the correct date in their systems if I ever needed assistance.
Not only did the discrepancy shortchange me the 90 days of phone support (which thankfully I didn't need), but it also reduces the window for purchasing AppleCare, if one wants to wait until near the 12 month period.
It's a bit of a hassle, but there's a section on Apple's site where owners can submit the proof of purchase and have the correction made. They asked for faxed copies of the proof, but if you press them, they'll also let you email scans.
As for AppleCare, it's just like any other form of insurance, as a hedge against risk. Everyone has their own tolerances.
Anecdotal stories imply that unofficially, having AC may curry favor when seeking repair, as well as make Apple more amenable to making repairs out of warranty.
When AppleCare is combined with a credit card extended warranty that is supplemental and takes effect
after the manufacturer's (like AMEX's), it can cover almost all of an item's useful life. With Macs, that's four years of coverage.