Plants vs. Zombies: Game of the Year Edition - Where is the Mac Download?

So, the PopCap games website where it advertises Plants vs. Zombies shows that it is compatible with PC and Mac under "System Requirements". However, when I purchased the game it only supplied me with an executable (Windows) file, and I see no option to download a Mac version. 

Here is the link where it advertises the game:

http://www.popcap.com/plants-vs-zombies-1

This is my first time buying a game from here... Am I just dumb? Have I overlooked something?