[ahofmann]

I think it was meant that Google has such high costs. I read somewhere that Google operates two atomic clocks in each of its data centers, but I can't find a source for it right now, just this: https://www.wired.com/2012/11/google-spanner-time/

[jnwatson]

Atomic clocks aren't all that expensive. You can get a decent rubidium one for US $5K.