I used to work for a small startup that wanted to know a lot about their users without breaking the budget. Redshift, a column-oriented fork of Postgres, integrates with lots of existing Business Intelligence tools. Best of all, pricing starts 0.25 USD per hour. We streamed user events from our application logs to Redshift. Then we wanted to know which users were doing what events. I wrote postgres_to_redshift after failing to find any other tool for streaming SQL databases to Redshift.