"(not set)" shown in Google Analytics for all Adwords data

Error

"(not set)" is shown in Google Analytics for all Adwords data

Solution

Link Account
Make sure you have linked Adwords and Google Analytics

http://support.google.com/analytics/bin/answer.py?hl=en&answer=1033961


Automated tagging
Make sure automated-tagging is enabled

http://support.google.com/analytics/bin/answer.py?hl=en&answer=1033981

Importing Cost Data
Follow the steps in "Importing Cost Data" section to apply cost data import

http://support.google.com/analytics/bin/answer.py?hl=en&answer=1034150