That small PDF symbol over the feature image helps set expectations for what format the download will be in. The arrow in front of the subheadline helps further direct your attention to important copy they want visitors to read. Like IMPACT, they also have an auto-checked box to subscribe to their newsletter on their form -- which, if turned into an opt-in check box, is a great way to increase subscribers. All of these small, seemingly insignificant details help bring together a solid, admirable landing page design.
The purpose of the transactional landing page is to persuade a visitor to take action by completing a transaction. This is accomplished by providing a form that needs to be filled out. The visitor information is obtained in order to add the visitor’s email address to a mailing list as a prospect. An email campaign can then be developed based on responses to transactional landing pages. The goal is to capture as much information about the visitor as possible. The ultimate goal is to convert the visitor into a customer.
Muzzle, a mac app that silences on-screen notifications, fully embraces this show don't tell mentality on their otherwise minimal landing page. Visitors to the page are greeted with a rapid-fire onslaught of embarrassing notifications in the upper left of the screen. Not only is the animation hilarious, it also manages to compellingly convey the app's usefulness without lengthly descriptions.
Trulia did something very similar to Bills.com with their landing page. It starts with a simple form asking for "an address" (which sounds less creepy than "your address," although that's what they mean). Below this simple form field is a bright orange button that contrasts well with the hero image behind the form, and emphasizes that the estimate will be personalized to your home.
Of course, implementing this isn't easy. You need to first develop your stories, then decide on how you're going to convey those stories and at what drip-rate. For example, your first email or two might go out on the day they first signup, then one email per day might go out afterwards. How much of that will be story-based and how much will be pitches?