With the rise in popularity of 3D printing, this point had to come. Warner Bros. and Microsoft are embarking on a new advertising campaign for The Hobbit: The Desolation of Smaug that will run on Windows 8 Ad-in Apps, followed later by MSN and the Xbox platform, that will – as part of its promotion – offer up a 3D printer design document for one of the motion picture’s props: the Key to Erebor.

The advertising campaign is set to go live from 13 December and will allow viewers to download the Key to Erebor blueprint from within the ad (previewed in Microsoft’s video below). The move does rely on interested parties having access to a 3D printer able to recreate the prop but Microsoft believes that they are “…providing a genuinely valuable and unique experience that puts the consumer first – really benefitting the people it reaches”.

They might not be wrong, depending on how this goes over with viewers we might see more 3D blueprints being offered as part of a promotion, giving advertising targets (that’s all of us) something tangible for their troubles.