title: Pusher vs Pubnub vs open source Socket.io / SignalR.net / Faye / jWebSocket
body: <p>I'm evaluating Pusher and PubNub at the moment to enable bi-directional realtime communications between my primarily web clients and my servers.  Both look impressive, with Pusher's docs seeming to be better, and PubNub's scalability and reliability clearly a strong point for them.</p>
  
  <p>However, as I am managing a budget, I am concerned that Pusher &amp; PubNub costs may become an issue for us, and am therefore considering using one of the open source alternatives out there - I've looked primarily at Socket.io, Faye and jWebSocket.  </p>
  
  <p>I have my concerns though running the service myself though:</p>
  
  <ul>
  <li>Has anyone actually scaled a Socket.io or other open source solution to multiple servers before?  PubNub claim to deal with <strong>1M messages a second!</strong>, I somewhat doubt Socket.io could do that without an unfathomable number of servers, if it would work at all.</li>
  <li>Are there features in the paid services that I am likely going to miss down the line should I go with the open source solutions?</li>
  <li>Is latency really going to be a concern if I have my server on AWS anyway?  PubNub are in multiple locations so I expect this should reduce latency although if a message needs to be sent from the US to Japan, having a server in Japan wouldn't help with latency as it still needs to travel there one way or another.</li>
  </ul>
  
  <p>Thanks for the advice.</p>