Paper Napkin slashes the, uh, transaction costs of rejecting:
"...If someone random asks you for your email address so they can contact you for a date, give them an email address @papernapkin.net (write it on a cocktail napkin for maximum effect) and we will send them a rejection message."
Actually, if you geek out with me for a second, this is an absolutely beautiful
example of unintended consequences. That's because it slashes the cost of getting rejected
as well as rejecting. This lowers the price of hitting on random people and asking them for an email address. Since the price has gone down, the quantity demanded at equilibrium rises. The market becomes more efficient; more people - not less - hit on others for dates.