This is nice if you can afford to have atomic clocks in your data centers and whole infrastructure teams working on keeping your clocks in sync (read: if you are Google) but otherwise you're probably gonna have a bad time.
I think those clocks are coming down in price but the bigger challenge is the logistics - for whatever reason shared data centers don’t run in a GPS signal from the outside that all their clients can share.
Well within the price range of smaller data centers, ~$1500 to build the open source reference card published by the open compute project: Open Time Server