Big data will enable highly targeted real-time advertising based on consumer behavior and profiles. Sensors in devices and the internet of things will send consumer data to cloud servers, triggering ads tailored to thousands of individual profiles accounting for products, environments, and stage in the purchase process. As mobile devices and home appliances become more connected, they will act as conduits for this new form of "flow advertising". While challenges remain, agencies that can deliver relevant experiences to consumers at the moment of decision will benefit most from these new capabilities enabled by big data.