Which is a best practice for creating a mobile-preferred ad?
Use the same format and content as you’d use for a laptop ad
Integrate mobile Flash video ads
Use a mobile-optimized landing page
Put your most important information in the second line of ad text
Mobile-optimized sites make life easier for mobile users. A mobile-friendly display URL signals to the user that they should expect an enjoyable mobile experience.
Read more here: https://support.google.com/adwords/answer/6373216