Lets pretend that <A HREF="http://blogs.zdnet.com/Murphy/?p=1019&tag=nl.e622">you're responsible for email and scheduling for 60,000 employees</A> in 60 functional groups ranging in size from 15 members to 3000. They're all currently using Microsoft Exchange on Windows/XP desktops with Active Directory as installed in mid 2005. In that situation both the Windows desktop and active directory will be organizational givens you have no power to affect--in fact, you would typically be in the frustrating position that you get no respect for keeping Exchange running while the CIO simultaneously ignores your contributions to the organization and uses the relative stability you've achieved for email and scheduling to justify Active Directory, other Microsoft tools purchases, and the further imposition of centralized management on users.

On the personal side, messaging products that co-exist well with Active Directory but are functionally independent of it offer significant potential payoffs; most notably the opportunity to raise your organizational profile relative to that of others at your level. If you saved a few bucks by switching to Domino, for example, the organization's cost of running Active Directory would be completely unaffected, but the guy running that side of the business would suddenly have to justify a much larger share of his own costs--because right now you're carrying him, and getting no recognition for it.