[andrew311]

Good question. Here's one benefit. With Kinesis you can batch a bunch of writes to S3 that would have otherwise resulted in many small files in S3.

In other words, you can make small writes to Kinesis and then read out in larger amounts and write larger files to S3. This is a huge optimization for any job that runs across the data in S3. Many small files can really undermine performance in something like Hadoop MapReduce because of the additional request overhead.