I bought my Macbook with Snow leopard. I didn't purchase iWork then, just had the 30 day trial version which expired and I never renewed it. Continued the same was when I upgraded to OS X Lion. So, when I installed Mavericks, I was also able to download Keynote, pages and numbers for free. But my friends who purchased macs with Mountain lion are asked to pay in the App store. So, how does this work?