[skizm]

The donation isn't so much about piggy backing (although I see why it seems like that since I made that marketing comment). The money ensures that the sender is serious while not simply providing a platform for celebrity entrepreneurs to further enrich themselves (not what I had in mind while reading this guy's idea but an equally valid business model I suppose). As far as the sender and receiver are concerned the only thing the fee does is ensure that sender is serious about this email. You could just as easily collect the fee as the middle man and not distribute it to either. The charity thing just helps senders feel a little better about where their money is going (while helping the world suck a little less). Remember, people don't like feeling manipulated and paying a company to "prove" that you are serious about an email isn't something that would sit well with me.

The comparison I had in my mind is something along the lines of paying a fee to complete a bitcoin transaction. The fee is distributed to a "charity" of sorts (the bit coin miners) and goes toward making the world suck less (making sure the block chain is secure). Also it legitimizes the transaction so the sender knows these bit coins are the real deal. If that doesn't make sense feel free to ignore that last paragraph :P