I think this could work for some things but definitely not others. You're riding a razor-thin line between security (essential) and convenience/peace-of-mind (not terribly essential), with potential ethical implications.
"Authenticate with your voice using our voice recognizer app," for example, could be pretty superfluous, since it's about convenience.
"Keep your password safe by not storing it in plaintext" should definitely be part of the core offering, no matter the price point.
"Use our app through a custom VPN" could be offered for pay, since offering that service costs the provider something.
"Use our app through SSL -- paying customers only!" should again be a core product, especially since it does not cost anything extra.
"Pay us 5ยข and we won't share your internal data with advertisors" etc etc -- you can certainly see where this is going
"Authenticate with your voice using our voice recognizer app," for example, could be pretty superfluous, since it's about convenience.
"Keep your password safe by not storing it in plaintext" should definitely be part of the core offering, no matter the price point.
"Use our app through a custom VPN" could be offered for pay, since offering that service costs the provider something.
"Use our app through SSL -- paying customers only!" should again be a core product, especially since it does not cost anything extra.
"Pay us 5ยข and we won't share your internal data with advertisors" etc etc -- you can certainly see where this is going