The rising promise of mobile and the simultaneous decline of the desktop is "heaven and hell" for publishers, says Anna Bager, vice president and general manager of IAB's Mobile Marketing Center of Excellence. "Mobile is cannibalizing their Web traffic. They're not making money right now. But this is what happens in this stage of a medium's life." She adds that native ads "are probably perfect for this medium. But it's very hard to make money on them because it doesn't scale."