Suppose there is an issue that your political representatives are going to be voting on soon, and you have an opinion about it. You could go to an activism web site that gives you a message box where you can type something and promises to email it to the appropriate people. You could "sign" an online electronic petition. You could go to the politician's own web sites and send a message through their web form (if they have one). You could find a regular email address for them and send a regular email. Or if you're really motivated, you could write a paper letter or make a phone call.
Does anyone have any real, current information on what the relative impact of these approaches is? I imagine that a web message through the legislator's web site is the best free electronic option; the activist email factory web site mail seems likely to be treated almost as spam, while the direct email has to fight through the deluge of real spam that inundates any well-publicized email address. I also imagine that a message you have to pay to send (a phone call or a letter) gets a little more weight, but it is really worth it?
Does it matter whether you're contacting a state representative with a few tens of thousands of voters or a US Senator with millions, in terms of which method is the best use of your own resources?
If you believe, as I do, that none of these methods are really very effective, is there a better method out there that doesn't require orders of magnitude more commitment? (One assumes that if you camp out in their office for a week until you actually get to talk to the legislator in person, that has more impact, and we all know that if you give them a big campaign contribution, that has more impact, but these methods are not on the same level at all.)
I'm interested in hearing people's personal opinions, but I'm even more interested in sources that actually have more weight. Are there interviews with real legislators (or people that have worked in real legislators' offices) where they talk about this? Is there research?