The combined Vocus and Cision have acquired Visible Technologies, the New York-based social media monitoring and analytics company.

Vocus chief Peter Granat said the acquisition is a key part of the his company's quest to build "the ultimate PR tool."

The announcement included a quote from Burton-Taylor analyst Chris Porter, saying said social media is the fastest-growing segment of the $2.2B global market for PR software.

Chicago private equity firm GTCR acquired Vocus and Cision earlier this year.