lol, it's 2013 ffs, Apple fanboys or "slaves" aren't the only people Apple sells their iphone, ipad etc to. Majority of the sales aren't upgrades, get with the times internet tough guy.
The upgrade rate is what the market calls it when a costomer brings in a phone and trades it for credit on a new phone. There are plenty of people who hand the old one to their kid or sell it and buy a newest one for no other reason except that you're only cool if you have the latest iPhone.
Anyone who has never considered anything but an iPhone because that's what their fanboy friend told them to buy and it was the first so they won't try anything else is what I'm calling a zombies. I pitty them.