Wall Street Journal: Facebook is in the process of building new mobile ad formats and advertising opportunities it hopes will deliver more immersive experiences for consumers and greater value for its advertisers. An early version of the new ad offering demonstrates the ability to create fully-branded, interactive destinations within the Facebook environment, featuring full-screen video and product information. Facebook exec Chris Cox will take the stage at the Cannes Lions advertising festival in France on Monday morning to share an early vision of what these new mobile ad opportunities might look like.