a.k.a. location based advertising, LBA, geolocation
Advertisements that are matched to your physical location. For instance, if you're a teenager and you're driving by the local mall, your cell phone may suddenly ring to notify you that there is markdown on sweaters, discounted just moments ago in a brand-name department store. That's a location-based ad.
There is a lot of marketing hype surrounding this scenario, but the infrastructure for this kind of technology is in fact rolling out in Europe, Asia, and parts of the United States.