GeoAPI or SimpleGeo?
mattgalligan: We (SimpleGeo) have some large customers right now, however, can't really say who they are due to privacy policy.I can, however, describe some of the technology that we use.We've built the platform using a multi-homed, multi-master database solution we call GiselleDB.  It's based on Facebook's Cassandra, but we've forked it since then.  Basically we're able to handle lots of read volume, lots of write volume, as well as push the data to all of our data centers.  We're currently housed in three datacenters and will expand to more later.  Essentially this means we can handle plenty of volume and it's always redundant (with API failover if a datacenter goes down).I'd encourage you to get ahold of me (matt [at] simplegeo [dot] com) or our developer relations guy (andrew [at] simplegeo [dot] com) if we can answer some further questions for you.