I was trying to get FaceTime on my macbook to load up all the contacts from my iPhone via iCloud. I enabled iCloud contact sync on my phone and logged in on the macbook but only a dozen-ish contacts appeared on laptop.
The problem was that I sync all contacts via Google (Exchange) and my phone.
“Synchronize your Gmail contacts to your Mac by enabling the “Synchronize with Google” option within your Mac Address Book using the ‘On My Mac’ database. This will create a local copy on your Mac of all of your Gmail contact”
Of course, I found this on the Google forums and not on the Apple ones. Read into that what you will.