One of the gripes from Ubuntu power user regarding the Unity dash is “Apps for Download” [from the Ubuntu Software Center] that shows up in the dash. I myself am one of the people that didn’t like this. One, it takes valuable space in the dash, and two, there never seemed to be any interesting download suggestions. It could be that I already have all the good ones installed. :) Luckily, with Ubuntu 12.04, the “Apps for Download” feature in the dash can be disabled.
How to Disable
To disable “Apps for Download” in the Unity dash, you will first need dconf-tools installed on your system. It can be installed from the Ubuntu Software Center, or by running “sudo apt-get install dconf-tools” (without the quotes) in the terminal.
After dconf-tools is installed, press Alt+F2 and run dconf-tools to launch the dconf-editor. Navigate to desktop > unity > lenses > applications and uncheck the ‘display-available-apps’ box.