ARMONK, NY: The four biggest challenges facing marketing executives are social media, the proliferation of devices and channels, shifting consumer demographics, and the explosion of data, according to the 2011 IBM Global CMO Study.

The technology company conducted the survey through face-to-face conversations with 1,734 executives across 19 industries in 64 countries between February and June.

“One of the most interesting things is how stretched CMOs are feeling these days,” said Carolyn Heller Baird, CRM research lead at IBM, who was ...