Honestly, it does next to nothing. It's probably better than literally nothing, but if you can spare the 2 minutes to make a phone call, it's a much better use of your time.
I posted this a while back:
>Congress uses multipliers to figure out how predictive each piece of communication is (ie, how likely it is that a certain piece of communication will result in a change in voting behavior).
> I don't remember the exact numbers, but the hierarchy goes (in descending order): in-person visit to DC office, in-person visit to local office, physical handwritten letter, physical typed letter, phone call, email. The multiplier attached to email is close to zero.
(The exact method varies by congressman/senator, but the relative rankings are the same throughout).
I posted this a while back:
>Congress uses multipliers to figure out how predictive each piece of communication is (ie, how likely it is that a certain piece of communication will result in a change in voting behavior).
> I don't remember the exact numbers, but the hierarchy goes (in descending order): in-person visit to DC office, in-person visit to local office, physical handwritten letter, physical typed letter, phone call, email. The multiplier attached to email is close to zero. (The exact method varies by congressman/senator, but the relative rankings are the same throughout).
http://news.ycombinator.com/item?id=3264561