interesting. Higher than their example pricing which was based on 500k sessions/month with a sync at begin and end (https://aws.amazon.com/cognito/pricing/).

I find the aws pricing (and "cloud pricing" in general) fairly confusing, and the things is that you have to be so careful that the wrong checkbox isn't checked or something that opens the spigot to the credit card# you had to enter to try out the service on the free tier in the first place. Note that I saw that you can get an alert when it first charges anything via billing alerts (http://docs.aws.amazon.com/gettingstarted/latest/awsgsg-intr...), but still...