I convince people not to do this by making it potentially cost them: get out of the habit or end up double charged some day. Not true for the majority of ecomme

I convince people not to do this by making it potentially cost them: get out of the habit or end up double charged some day. Not true for the majority of ecommerce sites that handle doubled requests sensibly, but there's one poorly coded site out there just waiting to blow their bank account out.