Millennial Media released its January SMART report, which offers a range of data about activity and ad campaigns on its network. Here are a few of the top-level datapoints and findings:

• Smartphones represented 58% of our network’s U.S. Smartphone impressions in January – a 20% increase month over month.
• The iPhone’s OS represented 56.6% of our network’s U.S. Smartphone impressions in January. iPhone has held the leading OS on our network over the last five months.
• RIM’s OS experienced a 5% decrease in January but still held the second largest share of U.S. Smartphone impressions on our network with a 20% share

The January report also republishes InsightExpress data about the greater efficacy of mobile marketing and advertising (vs. online):

According to Millennial's discussion of the InsightExpress data:

Mobile campaigns in the Retail Vertical showed the largest differences between online norms in three of the five categories, Aided Awareness, Purchase Intent, and Unaided Awareness, with index scores of 14, 7.9 and 5.7 respectively, according to InsightExpress.

The Travel, Automotive and Technology campaigns had similar increases above online norms in the Mobile Ad Awareness category with index scores of 4.8, 4.7 and 4.6. For advertisers, this is a potential positive indicator that consumers are more aware of advertising in these verticals. CPG campaigns indexed high in the Brand Favorability category with a 11.3 index score. The second best index was 7.0 for Automotive campaigns. In our Q4 Top 10 Mobile Ad Verticals, CPG ranked seventh while Automotive ranked tenth.

This better performance of mobile (vs. online) makes sense because of reduced ad clutter in mobile, the greater share of voice and the greater novelty of mobile advertising (so people notice). As mobile becomes mature some of these metrics may decline -- but that remains to be seen.