Really? Companies don't still make copies of their databases for analysis purposes?

Yes, but even then, they're populated incrementally - and sometimes very frequently. I don't know this for a fact, but I've been told by multiple people that the Chicago Transit Authority updates their analytic databases every five minutes. (That's a bit extreme.)

You could go into 10 different companies using SQL Server both for OLTP and OLAP (or OLAP-style) functionality, and find 7-8 different storage and update approaches.