I blogged a bit about how I'm using AWS Athena and Firehose at Ratelim.it to record and process usage logs. It's been super satisfying and easy to get going and cheap as anything.

http://blog.ratelim.it/blog/log-aggregation-at-scale-for-cheap-with-aws-athena-and-kinesis-firehose

If you've got a ton of data that you just need to get to S3 and you have irregular access patterns this seems like a fabulous solution. Amazing to have a Presto cluster at your fingertips for mere pennies.