Mobile advertising is a crucial tool for successful marketers as mobile moments play an increasingly prominent role in consumers' decision-making processes. It is partly for this reason that mobile ad spending growth continues to outperform overall digital ad spending. Marketers therefore need to understand how to allocate their digital ad budgets effectively on mobile. This forecast discusses how marketers' spending on mobile varies by channel and the factors that will drive growth in these channels — online display, paid search, and social media.