FourSquare Style Case Studies

Walter Riker, author of the excellent introductory Ease of Blogging space, points me to a good set of examples of using FourSquare type methods. Thanks Walter. How is it being used, effectively or not? See in ClickZ: The Best and Worst Campaign Deals on Foursquare's Turf. I note that the value metrics here are those to the consumer, not directly to the brand. Assumption here since these are big, well known names, the publicity and then sales will follow from the medium. Not always the case.