Instead of zip, deliver as a dmg.
This is the normal behaviour. Also, Mac Users will have less difficulty to find the installert because it either will open automatically on the desktop when the dmg is mounted, or, it will appear on the desktop after they opened the dmg.
Most Mac (and PC) users do not know where their downloads go, also they dont know the difference (and dont see it) between a zip file and a uncompressed zip file.
Customer support service by UserEcho