Google Adwords policy adjustment for display URLs 
The display URL is the URL displayed on your ad to identify your site to users. Google adjusted their display URL policy for sites that sit on shared or hosted domains (such as blogspot.com) to make this more clear.
As from this week, all ads leading to sites on hosted domains will need to have display URLs that accurately reflect their destinations.
Let’s say I wanted to create an ad linking to this blog: http://adwords.blogspot.com. In the past, blogspot.com would have been an acceptable display URL. Because there are so many independent blogs hosted on http://blogspot.com however, we now require the display URL to reflect the specific blog reached upon clicking the ad– in this case: adwords.blogspot.com.
Incorrect:
Destination URL: http://adwords.blogspot.com
Display URL: blogspot.com
Correct:
Destination URL: http://adwords.blogspot.com
Display URL: adwords.blogspot.com