Paul Ramsey on using PostGIS on Amazon RDS:

With Amazon Web Services, I had a backed-up and replication-ready database up and running in under an hour, and OpenGeo Suite tied into it in another hour. With the knowledge I’ve gained, next time will take only a few minutes.

Think about that for a moment, a few minutes and you can deploy an enterprise GIS solution.  Life is easier when you don’t have licensing constraints.