I've installed conky using sudo apt-get install conky-all and followed this tutorial to configure. The configuration works properly in Unity desktop in Ubuntu 12.04 and everything seems OK, However using Gnome 3 nothing appears on the desktop.
I have used following command to invoke conky at startup sh -c "sleep 20s; conky -c ~/.conkyrc".

Please suggest what additional steps need to be taken in order to make it work in Gnome shell Ubuntu 12.04.

Here is the .conkyrc file.