Getting employee buy-in is important. An employee that is engaged, that believes he has a higher purpose than just working for this company will put more effort and pride into his work.
While that is definitely important, I find that management buy-in is more important. More specifically, director/VP/C-level management. Managing remote workers or teams is more difficult than helicopter micromanagement. Bad, insecure managers need to see you working; good managers look at your productivity. Measuring productivity is hard, it's difficult to put numbers on. Seeing that you're warming your chair is much easier.
I recently was working from home 40% of the time or so. Every Friday, other days as required (two small children, do the math) with just a notification to my manager. Then I switched managers and the new guy put together a spreadsheet showing all the days I'd worked from home in the previous couple of months. After pointing out that four of the days he was talking about were actually sick days (which I reported as such, and had the time taken out) and showing how all the non-Fridays I'd taken from home were for legitimate reasons (my son having surgery, etc), he took away the privilege anyway. By his own admission, I'd done nothing wrong. (He then went on to tell me, in the same breath, that 1) I should collaborate more with my co-workers, and 2) I should figure things out on my own. Then he told me that my 2.5% raise could have been 3% had I performed better. Gosh, I feel so motivated now.)
The problem is not that I was working from home too often. The problem is that he's a shit manager. All of his reports hate him. If his boss (or his boss' boss, the CEO) was fully on-board with remote work, then he'd have a harder time being such a dick about it.