While using ampq or xmpp (rabbitmq or ejabbered that could have couchdb as backends) seems like a good fit to deliver real time updates about friend state in a social gaming platform where updates are small but frequent, I can't help but think why wouldn't couchdb be a good platform to deliver such updates?

The main advantage I could think of is its ability to filter updates based on friends and availability of changes api, which makes developing such an application and managing it (including replication) quite easy compared to ampq or xmpp where you have to think about how to manage the pubsub nodes and who is subscribed to them at any point in time.

However, I can't help but think this is too good to be true, I can't find information on what couchdb's shortcomings are. Somehow, it feels like using MySQL for message passing which is why I am hesitant to using it.

Anyone have any experience in using couchdb for such applications? would you recommend another platform to use?