[jolynch]

Thanks I'm glad you liked it! Your point on distributed transactions is very true, using CAS is what I meant by "transactionally advance a summary".

  For example, you could place a unique identifier on every count event and then roll 
  up those deltas in the background and transactionally advance a summary, either 
  preventing ingestion after some time delay or handling recounting.

Certainly transactions can help, but you still have to data model correctly for failure.

[rubiquity]

Thank you for pointing that out. I misinterpreted that bit to mean something less accurate than CAS.