Why are there shopping links in the dash?
In addition to helping you find apps or files on your computer, the dash also shows you related online results for your searches. Online sources include Amazon.com and the Ubuntu One Music Store and more online sources will be added.
When you purchase music or products from these sources, Canonical receives a small portion of the profits in exchange for directing more business to these stores. Canonical, the company that created and continues to support the Ubuntu project, then uses this money to make Ubuntu better.
Turn off online search results
If you don't want to receive online search suggestions, you can easily disable this feature.
Click the icon at the far right of the menu bar and select System Settings.
Switch off Include online search results.
and log back in for the change to take effect.