How many products are there where privacy is a core part of why it’s successful?

I’m leaving scale of “success” ambiguous so I get more answers.

Working on building zkTLS infra/products. A ruthless empiricist and meme connoisseur.

http://opacity.network

Although it's one of the least private social networks out there, people think Snapchat is private and it's the core reason it is used

I'd also say

* Protonmail
* Any VPNs 
* Tor
* Duckduckgo
* Signal
* Privacy badger 
* Brave 
* Password managers
* Fathom Analytics
* Privacy . com
* Purism
* Obvs TC, Zcash, Monero