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.
The fix:
“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.