Free Mavericks upgrade… I was not expecting that.
All the way from Snow Leopard too.
If Microsoft releases Windows 9 for free, do you think Apple will pay people to upgrade to the next OS X? :)
Giving old hardware a free software upgrade that enables it to run newer apps is a nice way of proving to the user how slow their old hardware is, as evidenced by older iPhones getting new iOS and people complaining about how laggy it is.
It is kind of strange that desktop OS upgrades are expected to cost money but mobile phone and tablet OS upgrades are expected to be free.