So let's say, hypothetically, you run an online store and you want to do some analytics over a proportion of your customer base.

The Amazon solution here, with the stuff they've launched today is;

a) use Kinesis Firehose to take a stream of log events from your app and dump those into S3 (gives you decent-reliability replicated backups)

b) ETL those using COPY into Amazon Redshift (a column store; very fast full-table scans)

c) point QuickShot at Redshift to draw graphs

so, yeah – but most of the data you want likely doesn't fit in Excel (or rather most of the work is reducing the data in size until it could).