Notice here that I'm recommending e-mail and computer systems be owned by campaigns, and by parties themselves. Investments by both will be necessary. But it's the skill of the human interaction with these systems that will make the difference between victory and defeat, not the money involved. This again gets back to the question of moderation. The database should be able to parse multiple responses, all approved by Sen. Cleland beforehand, and delivered to these different audiences.
Democracy is about compromise.
Most issues demand compromise. Compromise is anathema to advocates. The best politicians know how to take all this into account. Some will use the information in their databases to take the easy way out on issues. I think these politicians won't be successful.