If you are a start-up, I second the approach of dumping logs into Redshift. Lots of start-ups are doing exactly that (including yours truly).
Few things to keep in mind when you do that:
Create separate schemas for your raw data and your analysis. Dump the logs into a "raw schema", run your aggregations, and write the results to a "data schema". Once your data grows and you're running more reports, it will make your life much easier.
Separate your users from the start. Create a user each for your data loads, for your aggregations and for your ad-hoce analysis. As you ramp up query volume, the separation of concerns will make it easier to use the Redshift workload manager and keep concurrency high.
Ping me if you have more questions about the set-up. lars @ intermix dot io