Proclaim is a subscription because it allows you to get the newest features in Proclaim as soon as they are available. Instead of waiting for the new release and paying a few hundred dollars you get instant access to the new features.
All of these major features were added to Proclaim with no extra cost to any group:
This is only a small taste of what you get with a Proclaim subscription. Even the smaller updates that help you find media faster or give an updated look to the app are all free! Updates are included with your price!
Finally, you get great customer service. The Proclaim Forums are a great resource where you can connect with the developers as well as other churches who use Proclaim. Get quick responses and help people learn to get the most out of Proclaim.