Publishers such as Pandora (P), Twitter, and Facebook (META 0.73%), are quickly gaining market share in mobile display ads. Is Google (GOOGL 0.50%) threatened? Fool contributor Daniel Sparks tells Fool.com's Erin Miller in the following video that the development shouldn't negatively affect Google's stock. After explaining why, he tells investors how they should think of this trend and what they should keep an eye on.