I argue that the email itself is only 50% of the battle in an Email Marketing Campaign. How easy is it for recipients to get their incentive, fill out a form or make a purchase after the click? Is it clear to them what they are supposed to do? Does it tie back into the offer/message they just saw in the email? Blog post: http://emailmarketingtips.verticaltraction.com/2010/01/30/dedicated-landing-pages-the-other-50-percent-of-your-email-marketing-campaign/