Spok Holdings, Inc., formerly USA Mobility, Inc., is a holding company, which operates through its indirect wholly owned subsidiary, USA Mobility Wireless, Inc. The Company is a provider of wireless messaging, mobile voice and data and unified communications solutions in the United States. In addition, through its indirect wholly owned subsidiary, Amcom Software, Inc. (Amcom), it provides mission critical unified communications solutions for contact centers, emergency management, mobile event notification and Smartphone messaging. It operates in two segments: wireless operations and the software operations. It is a provider of paging services and selected software solutions in the United States and specifically in Europe and Australia. It offers services and products primarily to three market segments: healthcare, government and enterprise.