The other day, Google emailed me on my AdWords account that "35% of people who saw ads for your 'RustyBrick' campaign were on smartphones," in the last four weeks. Google then suggested I "create ads specifically for the small screen." With a big call to action to "create my mobile ad."
It is cool that Google actually sent me that 35% stat. In fact, almost 50% of my overall traffic is smartphone or tablet, 43% specifically is smartphone for my RustyBrick web site. But I guess those specifically searching for RustyBrick in Google and see a Google ad is 35%.
Here is the email Google sent me:
These are highly actionable emails and I suspect they work pretty well. Of course, Google wants advertisers to create more and more ads, so this should help.
Forum discussion at Google+.