You mentioned Ross Perot. Mr. Perot jumped into the race at the last minute, had one issue that he ran on, the budget deficit, was in and out of the race a couple of times, and still got 20 million votes, didn't have the Internet.
One serious drawback about letters is that, in order to get them, one must send some out. When it comes to the mail, I feel it is better to receive than to give.