AdAge has some details on the campaign here, but I obtained some raw figures from AdMob. Of those users who clicked on the Land Rover advertisement, 23% responded to at least one call-to-action on the landing page. 88% of those users watched the video, 9% entered their zip code to find a nearby Land Rover dealership and 3% used the click-2-call action, all of who were highly qualified leads. Of the 3% who clicked to call through the advertisement, 50% of the calls lasted more than 30 seconds and 20% of the calls lasted for more than a minute. Sales figures from the campaign were not available, but consider that the campaign was only 400,000 impressions; if LandRover had managed to sell one or two cars it would make the campaign more than effective.
The results would seem to indicate that the iPhone has become a more effective means of targeted mobile advertising campaigns than regular phones; the integration with Google Maps and the display of video provides a richer experience for both the viewer, and for the company seeking to expose their product.