Important question saurik! Our primary store is mongo. All data is replicated in different availability zones and at least one additional replica which is kept in a different ec2 region. A running snapshot backup is also taken at least every 30 minutes. Simperium isn't a messaging service. Every change is persisted and versioned. So for the Simplesmash demo, you could have a slider that would allow you to go back in time and replay movements. A note on versions: they are stored in an RRD like fashion. At first every version is kept, and as they accumulate; older versions are compacted and become less granular. We plan on making what level of granularity is kept an adjustable option in the future.
There are a lot of people in this space. By specializing your sign up is slightly more streamlined than groupme .. but only slightly -- http://groupme.com/ -- how do you see yourself comparing with them?
I wonder how much inspiration they have taken from there. It looks like they have uploaded their demo site to: http://dane2.staticloud.com/
Who would be the target market for this sort of service. It is potentially quite niche. Is it targeted towards users technical enough to be able to write html, css, and javascript. But not technical enough to use say Amazon's new static web site options on S3 http://bit.ly/h1rcJ8 or github's static hosting option?