Yesterday we met with Andy Miller, the founder/CEO of Cardstar. Until recently I hadn't heard of the company, although its iPhone app has had over a million downloads and has received some fairly extensive coverage in the NY Times and other tech blogs (where was I?). Miller is not the same Andy Miller who is the CEO of Quattro, in case you were wondering.

We had a long conversation about the app, some of the use cases and future scenarios and about the fascinating data being collected in the background. The data this company has is a retail gold mine. But that's a story for later.

The company started because Miller was carrying around too many loyalty cards in his wallet. This app, coming soon to Android and other platforms, allows users to enter their loyalty card account numbers and keep them all "on file" in a single place:

Part of the "secret sauce" here is that the company can generate a scannable barcode for any loyalty program -- that we're told works with current scanning technology.

The app, which Miller said has much more retention and usage than the majority of "lifestyle" apps in the iTunes store, also becomes a platform for push marketing to users and a way for SMBs to create loyalty programs in addition to the traditional big companies on the list above. As I mentioned, the data that Cardstar is collecting on usage (by demographics, location, etc) and engagement literally represents a treasure trove of "best practices" advice for grocery and retail marketers.

There's an intriguing and widening roadmap for this product, which began as a convenience for consumers. 

A novel element of the service, Cardstar allows users to create a physical "master card" that can carry up to six loyalty barcodes on a single piece of plastic, to minimize clutter (for people who don't have smartphones or want a backup for their most frequently used cards). You enter the account numbers on the Cardstar site and then receive a physical card in the mail. 

Cardstar is a fascinating company that sits at the intersection of offers and deals, which is fast-growing category online, and mobile loyalty marketing which is already very powerful. In terms of the latter category, we ran into Jay Highley, formerly of Tetherball360. We discussed some of the response rates to these mobile loyalty campaigns and he was sharing data from actual campaigns, which saw response rates of 20% to 40% in some cases. 

These numbers are amazing and show that "mobile marketing" and opt-in loyalty programs will be an increasingly important part of companies' mobile strategies -- or should be.