It isn't a problem if you're speaking specifically about Cloudant. They co-locate clusters next to your app as best they can (as Mike has mentioned elsewhere). That makes the network you're running on critical, however.

When we built out our message queue offering at SoftLayer (which uses Cloudant/BigCouch as a data store), latency out to the DB cluster simply never ended up being an issue. Properly leveraging DB features, I/O priority tuning, the caching tier behaving properly - all more often these end up being the culprit in performance issues.

What you need to better understand when considering a cloud-based data store is who's running your cluster. When it comes to guys like Adam, Mike and Robert, you're going to be very hard-pressed to find better (and available to you) talent in the CouchDB world. We certainly appreciate having them around.

It's not a problem if they're both in the same data center, not sure who cloudant are using though.

(Mike Miller, Cloudant). Exactly, we run cloudant clusters in nearly 20 data centers globally on many different providers (ec2, softlayer, rackspace, joyent, azure, hostway, ...) so we make sure that the data and application tiers are co-located.

Dealing with direct connections from mobile is more fun.

You should address this more clearly on your sales website. It's the first question people will have regarding using a database-as-a-service.

So mentioning the data centers you are in would be helpful.

You're right, we should address that more clearly. Thanks for the feedback.

Seriously do. I spent a few minutes looking for the list of data centres. And when I couldn't find it I left with the assumption that it was going to be a slow, pricey mess.

Nothing is more important than transparency when you are providing core infrastructure.

Actually you know what would be even better. I provide an IP address and you tell me the best, worst and median response times for a simple request.