On: Be Careful with UUID or GUID as Primary Keys

[_kyran]

The benefit of an external guid is that it obfuscates counts.

I've seen cases where it's possible for a business to track a competitor's growth by watching a public facing user id count increase.

[user5994461 → _kyran]

I do that too.

Ask an invoice from a HN startup. See the reference number at the top "2017-0000438".

They had 438 potential customers this year :D