We aim to develop a new pub/sub service through our XMPP-based platform for mobile social channeling applications. This pub/sub service is required to support the dissemination of publications from the social channels to billions of mobile clients with general interest as well as those with specific interest. Due to the wider reachability of publications, this pub/sub service imposes higher scalability requirement than the conventional ones. Meeting the scalability requirement becomes even more difficult when the pub/sub clients are geographically distributed and exhibit highly dynamic behavior. Given the dependency on the XMPP-based social channels as a substrate for publication dissemination, we first employed the state-of-the-art implementation of the pub/sub extension to XMPP servers. However, this implementation falls short in handling the aforementioned global scale and dynamic nature of our new pub/sub service. Therefore, we address the shortcomings by devising a new XMPP-based pub/sub system called SES (Scalable Eventing System). SES facilitates pub/sub communication on inter-regional clusters of pub/sub servers. SES improves scalability through a novel loadbalancing technique that adapts consistent hashing and virtual node placement strategies. Also, the procedure of publication notification is enhanced for higher throughput and lower latency. We demonstrate the advancements through empirical analysis conducted on Amazon Elastic Compute Cloud (EC2).