In early Dec 2011 the Mobile Marketing Association released a new set of standard ad sizes for both publishers and advertisers.
These standard ad units will help ease the transition into mobile as the medium becomes an everyday part of the media plan and a number of local media mobile sites have already adopted some of these ad units (300x50, 320x50 and 216x36 being the most popular).
Full-Feature and Smartphone Standard Ad Units:
- 300x250 (Smartphones Only)
- 300x50 (Smartphones Only)
- 320x50 (Smartphones Only)
Tablet Standard Ad Units:
Read more at the Mobile Marketing Association website.