Why does charging for access filter out noise?
Charging for access works because it moves the cost of a message from the person reading it to the person sending it, and only someone with a genuine reason will accept that cost. A spam filter guesses at intent from wording, whereas a price makes the sender demonstrate it.
The economics in one paragraph
If sending costs nothing, the rational strategy is to send to everyone, because one reply in a thousand still pays. If sending costs something meaningful, that strategy collapses immediately, and the only messages worth sending are the ones aimed at the right person with a real question.
Why the money goes to the recipient
A fee paid to a platform would simply be a toll. Paying the person who spends the time is what makes the exchange fair, and it is why the recipient keeps 95%. It also gives the recipient a reason to answer well rather than quickly.
Why the sender is protected too
The payment is authorised, not taken. It is only captured if a considered reply arrives inside the response window. That makes the promise symmetrical: the recipient is paid for their attention and the sender is charged only for an answer.
Set a price on your attention
Create a profile, choose your price and only screened enquiries reach you. You keep 95%.