Google announced today that mobile website optimization now factors into mobile search ads’ quality score. Mobile AdWords ads that point to a web site optimized for mobile will receive a higher quality score. That translates to higher visibility at a lower cost-per-click for those ads.
Google had already begun penalizing ads that pointed to flash-heavy landing pages last year. Flash does not work on many mobile devices, most notably the very popular iPhone.
For those sites who are not yet mobile-optimized and lack the resources to get there, Google recently began offering a free Google Sites tool that converts your site to a mobile version.