As this election heads toward what looks to be a photo finish in 15 days, there are really two presidential campaigns happening. There's the one on view in debates, campaign ads and big speeches. And then there's a stealthier one, with messages tailored just to you and delivered not in front of TV cameras but right to your mailbox. It's called micro-targeting, said Sasha Issenberg, author of a new book titled "The Victory Lab."

Read more http://feeds.abcnews.com/click.phdo?i=1bb45129ded6ba38b1bdd88eec77190a