With a vast majority of Internet consumption stemming from mobile devices, publishers are looking to optimize the performance of their digital properties through display ads and products like Google AdSense.
Choosing the right mobile ad units for pages is important and publishers must consider a variety of elements including viewability, size, placement and demand so that each mobile impression achieves a high value. By choosing the right or optimal ad size format, not only can you expect greater ad revenue, but you will be able to provide a much better user experience simultaneously.
Google recently published some guidance on what it has found to be high-impact mobile advertising formats. Based on its own data, medium rectangle (300x250), large rectangle (336x280), large mobile banner (320x100), and rectangular responsive ad units tend to get the best results.
Google suggests these ad units are high performers because they work well on desktop and mobile (with the exception of the large mobile banner) and will grab user's' attention because they are bigger and more engaging.