One thing to consider is that this is largely a self-correcting problem for Facebook due to the auction model for ads. As money leaves the pool, price per conv

One thing to consider is that this is largely a self-correcting problem for Facebook due to the auction model for ads. As money leaves the pool, price per conversion will tend to go down automatically for everyone else. If you think other advertisers will leave money on the table to make a point then you haven't worked in business very long.