Viacom utilizes MongoDB for its internal high volume polling, voting, and data collection service named Funnel, which supports over 100 global sites and experiences sudden spikes in votes during events. The system was developed to overcome limitations of previous unmanageable systems, providing flexibility and scalability with a single installation that can handle millions of votes. Funnel has processed over 10 billion votes across various events, demonstrating its effectiveness and performance in engaging audiences.