If you're not making an API, and you're just pushing data to your own client applications that you control, then Pusher and Fanout are more or less the same. Although you might like Fanout's simpler pricing model and our more open philosophy.
That sounds great actually.
We don't have an API now but we're planning to start one in the next 30 days and I was wondering about how we were going to do the real-time aspect.
I think I'm too biased to answer this properly. :) All of the realtime-as-a-service options have good resiliency. Pair one of them with RESTful AJAX for the chat db/logic and you'll do well.
If you're not making an API, and you're just pushing data to your own client applications that you control, then Pusher and Fanout are more or less the same. Although you might like Fanout's simpler pricing model and our more open philosophy.