Well, imagine its adopted. You want to reach someone but they are overwhelmed by incoming mails, likely skip yours. You can signal the importance by attaching some money to your message, so the receiver get paid for his time and attention
Or reverse it. People want to reach you and it is so important, so they attach money to reach you.
You can also sell. For example, I have baemails guitar lessons. One day, I may start sending them out, but attach sell price. So the receiver can only open them, if they pay.
You don't get spam in your inbox as with other providers.
Well, imagine its adopted. You want to reach someone but they are overwhelmed by incoming mails, likely skip yours. You can signal the importance by attaching some money to your message, so the receiver get paid for his time and attention
Or reverse it. People want to reach you and it is so important, so they attach money to reach you.
You can also sell. For example, I have baemails guitar lessons. One day, I may start sending them out, but attach sell price. So the receiver can only open them, if they pay.
You don't get spam in your inbox as with other providers.