It will reduce costs - Developers will have to spend less time checking an item in/out of a real VCS than their current ad-hoc approach.
It will protect the organization's intellectual property - this should be the most important consideration for any software company (other than data...). You are payed to create software - shouldn't it be accessible in its entirety?
It will provide quicker, more reliable and straightforward backup mechanisms - all VCSs have built in dumping capabilities. These tend to be more mature than a simple file copy.
It will act as a communication mechanism between developers - depending on the version control system you may use comments/labels/checkout status to determine if someone else has worked on a file, if it has been promoted to production, if it has a corresponding support ticket number etc.
It streamlines development - the ability to compare versions of files as well as the other mechanisms will be beneficial to your company period.
