Here's my advice as someone who used to play a number of MMOGs. There are three very important aspects to a voice communication system which vary in importance based on the particular game:
1. Latency and quality. These factors affect whether other players can hear you in time, and whether they can understand what they heard. These are very important for fast-paced situations where you can't afford to repeat yourself, a simple example being arena combat in WoW. Ventrilo is almost always used over Teamspeak for these situations. These sort of high-tension situations rarely have more than ~40 people involved, since once a group reaches a certain size the latency of the entire groups' action becomes higher than the latency of any voice chat.
2. Management. Can you mute people who are causing problems? Can you have a "commander-only" voice system to communicate between a few people in a channel without the others hearing? Can you kick people and ban spies? Is this all easy to do?
3. Scale. While Ventrilo is widely used in WoW, Teamspeak is used in EVE Online almost exclusively. Why? The reason is scale--there are often fleets of 100, 200, 500, or more players and the voice chat system needs to handle at the minimum a broadcast from a single commander to all of them.
Without the appropriate level of effectiveness in these categories, you won't be able to compete with existing apps.
1. Latency and quality. These factors affect whether other players can hear you in time, and whether they can understand what they heard. These are very important for fast-paced situations where you can't afford to repeat yourself, a simple example being arena combat in WoW. Ventrilo is almost always used over Teamspeak for these situations. These sort of high-tension situations rarely have more than ~40 people involved, since once a group reaches a certain size the latency of the entire groups' action becomes higher than the latency of any voice chat.
2. Management. Can you mute people who are causing problems? Can you have a "commander-only" voice system to communicate between a few people in a channel without the others hearing? Can you kick people and ban spies? Is this all easy to do?
3. Scale. While Ventrilo is widely used in WoW, Teamspeak is used in EVE Online almost exclusively. Why? The reason is scale--there are often fleets of 100, 200, 500, or more players and the voice chat system needs to handle at the minimum a broadcast from a single commander to all of them.
Without the appropriate level of effectiveness in these categories, you won't be able to compete with existing apps.