I think the "db in browser" idea is interesting because it makes the user pay for the compute for many more of the typical DB tasks. Any time you're in a situa

I think the "db in browser" idea is interesting because it makes the user pay for the compute for many more of the typical DB tasks. Any time you're in a situation where you're in an aggregation point you need to be wary of Moore's law; this is load balancers, database systems, log aggregation, etc. If your computers are getting N cheaper / faster per year, but you're getting M new clients and all your clients are also getting N cheaper / faster per year, you're going to be getting more traffic faster than you can scale, unless you figure out how to cheat. Cheating may be sharding your internal workloads, but it may also be "make someone else do the work."