is followed by
"I've called each of mine and have the vapid response letters to prove it."
Slight disconnect there? =)
Don't mean to harp on it, because contacting your congresscritters is a genuinely productive way to enact change. (Just don't put a whole lot of effort writing a heartfelt argument informed with evidence and rigor--its value comes more from indicating to the politician the breadth and energy of opposition to SOPA.)
But focusing on GoDaddy isn't a distraction, either. One of the central rules of political organizing is this: you pick the target, freeze it, personalize it, and polarize it. Victory isn't going to come in one fell swoop: if it comes at all, it will be through a loosely connected series of small victories, looking plausible only in retrospect.
GoDaddy is an easy enemy: it has an anti-charismatic founder who has a long history of general shittiness. A victory there doesn't only screw over GoDaddy, which is in the grand scheme of things not even a secondary target--its only actual goal is to make a quick buck from the feds. But what a victory does do is this: for one, it sends an obvious message to Congress and to other companies that the Internet matters: it's providing objective information that, yes, the anti-SOPA forces have some power, and other players might re-evaluate their current strategy to accomodate that new information.
But beyond that, and more important than that, is that it builds the movement. A victory sends a signal to people who are anti-SOPA but disenchanted that there is at least the hope of victory, bringing them back into the fold. It generates a bunch of news articles providing valuable anti-SOPA publicity, which is especially valuable since broader public knowledge of SOPA is one of the things we need most now. And it develops commitment and better engagement for the movement via showing how each of us as individuals can contribute to change.
It's not an either-or choice: you can both send letters and move your domains from GoDaddy.
By the way, if you're reading this and you haven't sent a letter... close out this window immediately, write a letter, and send it.