As in OpenPGP? Ease of use has to extend beyond software. How much do you trust your friends? Your friend's friends? People in the same city/occupation/age/soci

As in OpenPGP? Ease of use has to extend beyond software. How much do you trust your friends? Your friend's friends? People in the same city/occupation/age/social class/gender/race/citizenship? PGP has one threshold for transitive trust: three trusted keys trusting another key is good enough for your key to also trust it. In our capitalist society the easiest way for something to spread is a profit motive. Whoever spends the marketing resources to popularize it will have to recover their costs somehow. A lot of people will not pay for yet another subscription, and marketers will pay a lot to make their company look better.