Facebook now has publishers of all sizes using Audience Network, collectively accounting for 6% of all time spent in mobile apps. (If that doesn’t sound like much, consider that Snapchat and Twitter combined account for ~3%, according to Comscore). As the network has grown, there have been a lot of important but “tough” tweaks along the way, Vogel says. Like narrowing the amount of clickable area on its ads after studying heat maps, for example. Facebook knew that accidental clicks weren’t good for advertisers, so it tried to reduce them. At first publishers revolted at the lower click-through rates they were seeing, so Facebook had to convince them that they would make more money when they actually provided real value to brands.