I can’t think of an application that would use proof of human spending right now, I also couldn’t conceptualize Uber, or facebook 20 years ago.
Actually maybe I just did think of an application. If a payment is sent and it’s proven to be from a human, then there would be no need for me to complete a 3rd party captcha, since the whole point of a captcha is to prove you’re not a robot.
The interactivity opens up new uses of the If/then statement. What that could be used for, I don’t really know.
If the transaction was manually sent then: ?
If the transaction was sent by a human then: ?
I can’t give you a specific answer, but it’s kinda fun to think about.