It has been long been a challenge for many to develop effective ads that work across the differing screen sizes. Google plans to get to grips with that challenge with display and video ads that work effectively on mobile.

Today, we’re excited to announce that over the coming months we will launch several mobile display ad formats and tools across the Google Display Network, the AdMob Network and DoubleClick that will make it easier for advertisers to build successful ads that work across screens.Google to Launch New Mobile Display Ads [adwords.blogspot.com]