Say you're running a business offering "software as a service", and you need to run some kind of multi-tenant architecture. There are certainly some tradeoffs in ways to do that, but one of them is going to be SQL Server licensing, especially under SQL 2012 and the (very foolish, completely counter the trend to more cores, and not to mention complicated) per-core licensing for Enterprise.
So I want to check, when you license N cores in Enterprise, that's N cores of the server, split into as many instances as you might like, even overloaded by as many instances as you might like?
Or (doesn't seem likely, but ...) if you license say 8 cores, is that 8 cores per instance, and you can actually run three instances against 24 cores under a single 8-core license (really doesn't seem likely!).
Or, what's all this about a "web" edition:
http://www.microsoft.com/en-us/sqlserver/editions/2012-editions/web.aspx
"Benefit from log shipping, which helps automatically back up data on separate servers or keep multiple-read servers online to better handle large amounts of web traffic. Keep multiple nodes in sync by using this low-cost edition along with SQL Server 2012 Enterprise instances through one-way merge and transactional replication. New Database Recovery Advisor helps administrators create a more predictable and optimal restore sequence."
Those are fact questions.
Or is it time to chuck all this and try to buy stuff in the cloud?
That's more of an opinion question.
Thanks,
Josh