Each month, AdMob, a mobile advertisement marketplace, analyzes their ad request/impression data to look for trends in the mobile world. This morning, they released their Mobile Metrics Report for September of 2008. As their first report was for September of 2007, this release grants us the first opportunity to compare statistics with those of a year ago.
To clarify, these statistics are generated by the number of ad impressions/requests they get from each handset across the 5,000+ sites they serve. While such numbers may correlate to sales, these do not directly represent sales numbers.
