Mobile in-app advertising is growing rapidly and becoming a major revenue source for app developers. Spending on in-app ads is expected to reach $17 billion by 2018, up dramatically from $3.5 billion in 2013, making it the fastest growing mobile advertising sector. In-app ads can yield high engagement rates and click-through rates that are 2000% higher than other mobile ad formats. Luxury brands are using in-app ads to better connect with consumers and enhance their mobile experiences. The global mobile advertising market is also growing quickly and is forecast to exceed $24 billion by 2016, with search and location ads delivering the highest revenues.