As well as giving away OS X 10.9 Mavericks for free, Apple has also promised to update iWork and iLife gratis, too, for anyone that bought a Mac after October 1st. But there's a glitch in the system that means people with illegal or trial copies of the software are being given free updates too.
9to5Mac reports that a flaw in the Mac App Store seems to allow users with illegally downloaded or trial software to upgrade Pages, Numbers, Keynote, iMovie, iPhoto, GarageBand and even Aperture for free. 9to5Mac goes on to speculate that the bug is a result of boxed copies of the software not being tied to the Mac App Store system.
Aperture uses a unique serial number for each copy, but clearly the App Store is unable to check if an app has been activated or not. In turn, that means copies of the software that have been illegally downloaded and activated with a serial number thousands of times aren't being detected either. Essentially, the App Store seems to be merely checking if the software exists on the Mac, and not stopping to check where it comes from or who bought it.
Apple hasn't commented on the problem, though it has withdrawn trial versions of the affected software from its site, which suggests that it's not too happy about people getting their hands on hundreds of dollars-worth of software for nothing. That also, presumably, scuppers the plan you were just hatching. Sorry. [9to5Mac]