Throughout my career I've been looking to consolidate SQL Servers when I find them. The typical employer I've had usually grows their IT infrastructure over time and many projects look like this:

Build or buy a software package
Buy a new server
Install SQL Server and one database for the application

Over time this means I find lots of individual servers running at much less than full capacity. That's something that DBAs like, because it means that we can handle the inevitable spikes in resource usage that our workloads will encounter. However that's not what the rest of the business, especially the financial management, wants. Underused resources mean money that isn't spent well.
Read the rest of "Consolidation Matters" at SQLServerCentral.