I have a restaurant client that I've had for about 2 years. I have Google analytics for both the main site and the mobile site.
I just did a report for Q1 for 2012 and Q1 for 2013 for both and I was pretty amazed.
The main site unique visitor traffic was almost exactly the same from 2012 to 2013 (Jan-March), but the mobile traffic unique visitor count increased by a whopping 69%.
Local business owners that don't have a fast loading mobile site with click to call, map, hours, etc. are really missing out on this mobile trend. Little do they know how much business they could be losing.