Wikipedia
PubNub
PubNub is a global Data Stream Network (DSN) and realtime infrastructure-as-a-service (IaaS) company based in San Francisco, California. The company makes products for software and hardware developers to build realtime web, mobile, and Internet of Things (IoT) applications.
PubNub's primary product is a realtime publish/subscribe messaging API built on their global data stream network which is made up of a replicated network of at least 14 data centers located in North America, South America, Europe, and Asia. The network currently serves over 300 million devices and streams more than 750 billion messages per month.