Digital marketing is on the rise, but that doesn't mean that there isn't plenty to be worried about. A Harte-Hanks survey of senior marketers around the world found that more than half of the executives were concerned with security and privacy issues, the prevalence of spam, and the accuracy of their data.

eMarketer aggregates, filters, organizes and analyzes data from more than 1700 research firms, consultancies and government agencies around the globe.