A lot of companies have torn down the PC Berlin Wall and nowas well as PCs. Apparently, this creates some interesting dynamics for PC support people.
From what I've heard, most organizations settle in at approximately 95 percent PCs, and 5 percent Macs. Seems like a small and manageable percentage, but here's the rub. According to some services vendors and PC administrators I've talked to, a large portion of the Mac users are executives--CEOs, COOs, chief legal counsel, etc. These folks get top priority and can be very demanding, so network and endpoint administrators have to be on their toes and establish strong Macintosh "chops" quickly. As a result, some IT professionals claim that 5 percent of Macs may as well be 20 percent of the total PC population. Thus 5 percent equals 20 percent.
Historically, IT pundits would point to this inefficiency as a reason why organizations should not allow employees to use Macs. Heck, maybe some analysts still do. There is more in play than just labor cost and accounting here however. "C-level" people tend to get what they want and, obviously, they want Macs.
Do Macs make these folks more productive, creative, or engaged? I don't have any data suggesting that they do, but this would be a worthwhile study. In any case, if Macs make the mucky-mucks happy and a happy worker is a productive worker, those excess PC support costs may be well worth it.