Wow, old people use smart phones, too

London-based data junkie Dirk Singer notes the 35-54 age demo is now the most active group using mobile social networks -- those Twitter and Facebook apps on your cell phone. We chatted up this issue recently with mobile reps from Jagtag and Impact Mobile, who both agreed that mobile usage is "proving more elastic" among demographics than previously thought (that's marketingspeak for yes, old people use smart phones too).

Jagtag, for instance, provides a QR Code response system in which a consumer can snap a photo of a bar code image, email or tweet it in using her phone, and get a video or slide show back on her handset -- a useful way to bookmark information on a cell in case you don't want to dial in to a call center just yet. Jagtag told us that it recently ran a campaign for a large biotech firm in which posters at a state fair promoted "take a picture of this code for more information on soybean yields" -- and 14% of visitors at the fair did exactly that.

If soybeans work, could your product?

The distinction here is Jagtag gave staid consumers a clever way to respond to a message -- it did not push a banner ad onto their cell phones, but instead offered a more convenient way to get information if they opt in. That's an important point, because many marketers are rushing to push ads through mobile handsets, and frankly we're not sure outbound messaging will be welcomed in such an intimate space. Consumers certainly are not responding to the outbound equation; mobile ad spending forecasts have been missed for the past decade. The use of mobile as a new response doorway has more promise. Marketers, we all have phones in our pockets. Help us tap our way to you.